ALUMINUM 1
(II) Chloride.6 A facile reduction of aromatic ketones and alde-
hydes into corresponding alcohols is readily achieved employing
Al powder in combination with NiCl2·6H2O in THF.3
Reduction of (thiazolyl)(acylaminomethyl)ketones with the
Aluminum1
reagent prepared from Al dissolved in i-PrOH in the pres-
ence of Aluminum Chloride,7a and oxidation of aluminum tris
Al
(3-pentanoxide-1,2-d5) (from the alcohol, Al shot, and a trace of
HgCl2) with benzophenone,7b can be considered special cases of
[7429-90-5] Al (MW 26.98)
modified Meerwein Ponndorf Verley and Oppenauer reactions.
InChI = 1/Al
Aromatic nitro compounds are reduced to anilines with Al
InChIKey = XAGFODPZIPBFFR-UHFFFAOYAX
powder in AcOH HCl8 or with Al NiCl2·6H2O.3 Reactions
of nitrobenzene with Al turnings (heating in aq H2SO4)9a or
(reducing agent for many functional groups;1 can aluminate
Al Fe alloy (in 50% NaOH)9b afford p-aminophenol and N,N -
double bonds2 or insert into carbon halogen bonds; promotes
diphenylhydrazine, respectively.
propargylation of carbonyl compounds; in combination with
Al foil activated with HgCl2 and Hg is capable of reducing
metallic Sn or PbBr2 mediates Barbier-type allylation of carbonyl
both aliphatic10b and aromatic Shiff bases10b to secondary amines.
compounds or imines)
For aromatic substrates, the process is substantially complicated
ć% ć%
by reductive dimerization of the azomethines. It is this particular
Physical Data: mp 660.37 C; bp 2467 C; d 2.702 g cm-3;
reagent (not other metals such as Na, Mg, or Zn) that causes un-
Eć%(aq) Al3+/Al0 = -1.66 V.
usual ring contractions of lumazines11a and pterines11b to theo-
Solubility: reacts with dil HCl, H2SO4, KOH, and NaOH, hot
phyllines (eq 2) and guanines respectively, via a radical anion
AcOH; insol conc HNO3.
formed upon C=N double bond reduction.
Form Supplied in: silver-white, malleable, ductile metal; widely
available in foil, granules, ingot, pellets, powder, rod, shot, wire.
O O

Handling, Storage, and Precautions: Al foil is moisture sensi-
Me N Me N
Al(HgCl2)
"
N N
tive, powder is moisture sensitive and flammable. Aluminum is
aq MeOH NH3
reputed to be practically nontoxic.
O N N OEt O N N OEt
81%
Me Me
O
Me
N
N
Functional Group Reductions. Aluminum will reduce
(2)
ketones or aldehydes to alcohols or saturated hydrocarbons, ni-
N
O N
H
tro compounds and Shiff bases to amines, and alkyl halides to
Me
alkanes. Aluminum also effects reductive dimerization of ketones
and dehalogenation of polyhalogenated compounds. In combina-
1,2-Dehalogenation occurs when polyhalogenated substrates
tion with Nickel(II) Chloride hexahydrate in THF, metallic Al will
react with Al turnings in the presence of AlCl3.12 For alicyclic
reduce acyl chlorides, anhydrides and nitriles, epoxides, and disul-
compounds it is a stereospecific process (eq 3).12b
fides. Moreover, aluminum exhibits pronounced chemoselectivity
Cl Cl
in reduction of polyfunctionalized compounds.3
Br
Br
Aromatic ketones are especially readily reduced by aluminum.
Cl Cl
Br Al turnings, dry ether
Reduction of 2-methyl-2-phenyl-1-indanone with Al in i-PrOH
Cl
reflux, 3 h
proceeds with diastereoselectivity (trans/cis ratio in alcohol
97% Cl
Cl
Cl
formed is 90:10) better than that observed with Li, Na, or K.4 Cl
Cl Cl
Quinone (1) is reduced with Al in 85% H2SO4 to the 6,13-dihydro
(3)
Al
product (2) (eq 1) while the 6-hydroxy derivative is formed in
reaction of (1) with Cu in 96% H2SO4.5
Cl Cl
Br
Cl
O OH Cl Cl
Al turnings, dry ether Cl
N
Cl
Al 85% H2SO4
reflux, 3 h
Cl
73%
80 °C Cl Cl
Br
N
82%
Cl
Cl
H
O O
When 2 5% NaOH is added, Al (powder or turnings) reduces
(1)
O
H
1,1-dibromocyclopropanes or 7,7-dibromonorcaranes into mono-
N
bromides with modest cis or exo stereoselectivity.13 A small
(1)
amount of Al powder promotes halide exchange and
N
H
3-chlorophthalide is converted almost quantitatively into
O
3-bromophthalide in a reaction with dry HBr.14
(2)
On refluxing with an excess of an alkyl or aryl halide, Al inserts
Reductive dimerization of tetralone to 3,3 ,4,4 -tetrahydro- into the carbon halogen bond.15 Primarily a mixture of sesqui-
1,1 -binaphthyl is mediated by Al foil activated with Mercury halides 3 is formed (eq 4).15 With alkyl halides,16 the sesquihalide
Avoid Skin Contact with All Reagents
2 ALUMINUM
mixture formed in situ can be easily reduced to produce trialky- (HgCl2-activated) in i-PrOH promotes deoxygenation of epox-
laluminum compounds (eq 5).16c In case of aryl halides, (3) is an ides, giving the corresponding alkenes.27
excellent reagent for transfer of an aryl moiety from Al to other
elements (P, Sn) (eq 6).17 Mixture (3) also reacts with organic Friedel Crafts Alkylation Catalyst. Aluminum catalyzes
halides to form organoaluminum compounds. However, a more ortho-alkylation of anilines and phenols with alkenes.28,29 Pre-
versatile method of synthesis involves the reductive replacement formed aluminum anilides or phenoxides exhibit high suscepti-
of Hg from organomercury compounds with Al (eq 7).18 bility toward alkene attack and usually o,o -dialkylated products
predominate.29a,b Selective ortho-alkylation of phenol can be ac-
RX + Al R2AlX + RAlX2 (4)
complished using aluminum soft drink cans as the reagent (eq 9).28
X = Cl, Br, I (3)
OH OH Ph
octane
1. 0.15 1.0% Al, 140 °C
2 Al + 3 Mg + 6 BuI + 2 PhOEt
(9)
90 105 °C
2. PhCH=CH2
80%
80%
2 AlBu3 · PhOEt + 3 MgI2 (5)
Alumination Agent. A facile hydroalumination of carbon
PhCl, rt 180 200 °C, 2 h
Ph3Al2Cl3 + PCl3 Ph3P + 2 AlCl3
(6)
carbon double bonds yielding trialkylaluminum compounds takes
91%
sealed tube place in a three-component mixture consisting of an alkene, hy-
3 [H2C=CH(CH2)2]Hg + 2 Al
drogen, and Al (eq 10).2 The process involves intermediate for-
rt, 2 weeks
100%
mation of a dialkylaluminum hydride which adds to the third
2 [H2C=CH(CH2)2CH2]3Al + 3 Hg (7) alkene molecule, affording the trialkylaluminum. To elucidate the
mechanism of the reaction, direct synthesis of organoaluminum
compounds in the condensed phase from Al vapor and alkene is
Reduction of element halogen bonds by Al or Al-promoted
of noticeable importance.30
cleavage of other bonds is widely used in synthesis of organo-
boron,19 organosilicon,20 organogermanium,21 and organophos- 2 Al + 3 H2 + 3 H2C=CMe2 2 (Me2CHCH2)3Al
(10)
phorus compounds,22 as well as Ä„-complexes of titanium,23
vanadium,23b and zirconium.24 Al powder in combination with
Selective Propargylation. The problem of propargyl group
AlCl3 and Iodine (or Iodo(iodomethyl)mercury) induces boryla-
introduction in various substrates without propargyl allenyl rear-
tion of C6H6 with Boron Trichloride to form PhBCl2.19a Mix-
rangement has been addressed using alumination (Al in the pres-
tures of amines and triarylborates are reduced to borazanes by
ence of HgCl2) of propargylic bromides followed by addition of
aluminum iodine.19b On electrochemical reduction with a sacri-
a carbonyl substrate to the organoaluminum reagent formed in
ficial Al anode, chlorosilanes undergo dimerization20a or cross-
situ.31 This approach has been used to prepare propargylic alco-
coupling if two different chlorosilanes react.20b Tetraalkylger-
manes are cleaved by the system Al I2 to yield iodogermanes.21 hols from ketones32a and aldehydes,32b propargylic ethers from
Ä…-chloro ethers33a and acetals,33b acetals of propargylic carbalde-
A mild and neutral reducing system of Al NiCl2·6H2O THF
hydes from orthoformates (eq 11),34 homopropargylic ethers and
reduces enones to saturated aldehydes (eq 8),3 nitriles to amines,
sulfides from chloromethyl ethers and sulfides.35 Propargylic
acid chlorides and anhydrides to aldehydes, disulfides to thiols,
compounds prepared in this manner have been used in the syn-
and epoxides to the alcohols. Isolated double bonds, carboxy-
thesis of spirilloxanthin, 3,4-dehydro-rhodopin,32a ecdysteroid
lic acids, esters, lactones, primary, benzyl and allyl halides,
analogs,35 and lycorine precursors.36
aliphatic aldehydes and ketones as well as aliphatic nitro
compounds are inert to this agent.3
1. Al, ether
(11)
2. HC(OPr)3,  80 °C
Br OPr
Al NiCl2, THF
82%
PrO
CHO CHO
10 min
80%
(8)
Aluminum is presumably a unique partner for condensations
of this type because, for example, Zn always gives a mixture of
In combination with Antimony(III) Chloride, metallic Al alkynic and allenic alcohols.31,32a
smoothly reduces both aliphatic and aromatic aldehydes to alco-
hols (yield 50 98%). Reduction proceeds chemoselectively and Aluminum Tin(0) and Aluminum Tin(II) Systems. A
PhCHO is preferably reduced in competition with PhCOMe. Un- strong impetus for current applications of Al in organic synthesis
like Al NiCl2, reduction of Ä…,²-unsaturated aldehydes with this has resulted from a study on allylation of carbonyl compounds
system occurs only at the C=O group, leaving C=C double bonds mediated by the combination of stoichiometric amounts of metal-
intact.25 lic Al and Tin, and the observation of extensive acceleration in
the presence of water.37 Typical procedures suggest that a car-
Reactions of Aluminum Alkoxides and Phenoxides. A bonyl compound, allylic bromide, Al, and Sn should be used in
facile method of alcohol dehydration is based on thermal decom- a ratio 1:1.2 2:1:1. Allylation with unsymmetrically substituted
position of the derived Al alkoxide which, depending on the al- allylic halides proceeds with complete rearrangement in the al-
ć%
cohol structure, commences in the range of 200 270 C.26 Al foil lylic unit and shows considerable diastereoselectivity (eq 12).37a
A list of General Abbreviations appears on the front Endpapers
ALUMINUM 3
Intramolecular versions of the reaction have been used in synthe- in EtOH AcOH H2O. This reaction regiospecifically leads to 1-
ses of five- and six-membered cyclic alcohols.37c aryl-2,2-difluoro-3-buten-1-ols.42
CHO Aluminum Lead Bromide. Three main processes, Barbier-
Al Sn (1:1)
Br
+
type allylations, reductive coupling of carbonyls, and addition of
THF H2O (2:0.2), 2 h
polyhaloalkanes to carbonyls are mediated by this system which
81%
has been extensively studied in the past decade. PbBr2 is used in
HO
a catalytic amount (molar ratio Al foil:PbBr2 = 100:1 5), of great
importance because of the hazardous properties of lead.
(12)
Al PbBr2 promoted allylation of various carbonyl compounds
can be performed at ambient temperature in DMF, aqueous THF,
erythro:threo = 78:22
or aqueous MeOH while nonaqueous THF, MeOH, and MeCN
are not suitable. A moderate excess of allylic bromide (10 100%
A combination of Al powder (2 equiv) and Tin(II) Chloride
relative to carbonyl substrate) is recommended. Under these
(0.1 equiv) in an organic solvent is even more active than the Al Sn
conditions the addition to Ä…,²-enones proceeds regiospecifically
couple and addition of water to the solvent enhances the allylation
in a 1,2-fashion (eq 15).43
rate remarkably.38 Carbonyl compounds are almost inert to ally-
lation if 1 equiv of Al and only 0.1 equiv of Sn is used,38 whereas
O
metallic Sn or SnCl2 in aprotic solvents convert allylic halides to
allylstannanes in situ, which readily allylate carbonyl substrates39 Ph
OH
with complete rearrangement in the entering allylic unit.39a It has Al PbBr2 (1.1:0.03), DMF, rt, 2 h, 96%
+ (15)
been established that Al effects both oxidative addition of metallic
Ph
Sn to allyl halide and reductive regeneration of Sn0 from SnII and
Br
PbII
Pb0
SnIV for a recycle use.38 Thus all allylation reactions in Al Sn
or Al SnII systems can be considered as aluminum-promoted and
tin-recycled processes.
Al Sn mediated condensation of aldehydes with Ä…-(bromo-
AlIII
Al0
methyl)acrylates40 represents a facile synthesis of Ä…-methylene-
Å‚-butyrolactones (eq 13).40a This procedure is more efficient than
allylations promoted by CrII (see Chromium(II) Chloride and
Metallic Al itself does not promote allylation which is, how-
Lithium Aluminum Hydride).40b
ever, mediated by Pb Bu4NBr.44 The observed stoichiometry
(carbonyl substrate:CH2=CHCH2Br:Pb = 1:1:1) suggests that
Br
1. Al Sn, Et2O H2O, reflux, 12 h
the reaction involves an active organolead(II) rather than orga-
+ C5H11CHO
2. TsOH nolead(IV) reagent, in contrast to the tin promoted reactions.38,39
CO2Et
51%
The in situ generated Pb0 is much more effective than commer-
cially available Pb and turnover of the Pb0 catalyst in the range
C5H11
14 77 is attained.43
O
(13)
This type of Barbier-type allylation has been applied to C-3
chain elongation of cephalosporins.45
O
Acetals RCH(OMe)2 (4) as masked carbonyl compounds also
undergo Barbier-type allylation mediated by Al PbBr2 AlBr3
Almost exclusive threo diastereoselectivity is characteristic of
(molar ratio 1:0.03:0.1) to form homoallylic ethers (5).46 The
the reactions of cinnamyl chloride with aldehydes promoted by
presence of Aluminum Bromide is critical because no allylation
Al Sn41a or Al SnCl2.41b Aldehydes containing a chiral center
product is formed in the absence of this co-catalyst. Reaction path-
adjacent to the C=O group afford threo Cram and threo anti-
ways depend strongly on quantities of reactants and reagents, es-
Cram products with the former predominating (eq 14) in contrast
pecially in the case of acetals of aromatic aldehydes. An increase
to magnesium-mediated reactions of the same partners, which give
of AlBr3 from 0.1 to 0.5 equiv is accompanied by reductive ho-
all four possible diastereomers.41a
mocoupling to 1,2-diaryl-1,2-dimethoxyethanes (6) If the ratio
CH2=CHCH2Br to (4) is higher than 2:1, commonly used in such
t-Bu O
Sn Al, Et2O H2O
processes, diallylation and reductive homocoupling of monoally-
+
Ph Cl
rt, 24 h lated products effectively compete with monoallylation. The re-
H
>90%
sults reveal formation of cations (7) in the presence of AlBr3 as an
Ph Ph
acid catalyst. The cations are either further allylated or reduced
t-Bu + t-Bu (14)
by Pb0 to furnish dimers (6) (eq 16).46 Replacement of AlBr3
with Trifluoroacetic Acid (TFA) (1 equiv) causes a complete shift
OH OH
of the reaction toward formation of homocoupling products (6)
>9:1
from arene and heteroaromatic carbaldehyde acetals.47 To pro-
Unlike other allylation processes mediated by Al Sn, no iso- mote homocoupling, although less efficiently, VCl3 or Cobalt(II)
merization of the allylic unit is observed in the reaction of aromatic Chloride or Tin(II) Bromide can be also employed instead of
aldehydes with CH2=CHCF2Cl in the presence of Al 10% SnCl2 PbBr2 in the Al PbBr2 TFA redox system.
Avoid Skin Contact with All Reagents
4 ALUMINUM
OMe
OMe
PbBr
or in the absence of either NiCl2 or PbBr2. The latter can be re-
+
AlBr3 (0.5 equiv)
placed by BiCl3, SnBr2, or GeCl4, but dimer yields are remarkably
Ph OMe Ph OMe
Ph OMe
THF
decreased.53
(4) (7) (5) 40%
1. maleic anhydride
Al, PbBr2, NiCl2(bipy)
xylene, 180 °C
Br Ph
Pb/Al
Ph Ph
(16) MeOH, rt, 6 h
2. aq KOH
83%
E,E:E,Z = 97:3
82%
OMe
Ph
chloranil
Ph
Ph Ph Ph Ph (19)
xylene, 138 °C
OMe
81%
HO2C CO2H CO2H
(6) 40%
Both aromatic and aliphatic aldehydes undergo Al PbBr2 me-
An extremely facile procedure for C-allylation of imines in- diated reductive addition of polyhalomethanes CX3Y (X = Cl,
volves direct mixing of imines and CH2=CHCH2Br with a cat- Br; Y = Cl, Br, CN, CONH2). The reaction (aldehyde:CX3Y:Al:
alytic amount of PbBr2 (0.03 equiv) and Al foil (1 equiv) in ether
PbBr2 = 1:2 4:1.2:0.1) is performed in DMF, yielding Ä…-
containing Boron Trifluoride Etherate (1.1 equiv) (eq 17).48 With
(trihalomethyl) carbinols (8) in almost quantitative yield. These
almost the same efficiency, aromatic and aliphatic aldimines un- can be subjected to further reductive elimination with Al PbBr2 in
dergo electroreductive Barbier-type allylation using an Al anode/ MeOH containing aq HCl to produce 1,1-dihaloalkenes (9). When
PbBr2/Bu4NBr/THF/Pt cathode system where a combination of carbinols (8) react in DMF, reduction of the trihalomethyl group
sacrificial Al anode and Pb0/PbII operates as a mediator for anodic to a dihalomethyl occurs instead of elimination (eq 20).54 This ap-
and cathodic electron transfer processes, respectively.49
proach has been used in the stereospecific synthesis of pyrethroid
insecticide precursors54 and arylacetic acids.55
PbBr2, Al, BF3 · OEt
2
N Ph
Br
+
O HO
ether, rt, 10 h
Cl 94% Al PbBr2 (3:0.1)
CCl3
H + CBrCl3
DMF, rt, 5 h
86%
Cl Cl
N Ph (17)
(8)
H
Cl
Cl
Al PbBr2
Cl
aq HCl MeOH, 50 60 °C, 7 h
Regarding the chemical allylation of imines, PbBr2 and the Cl
83%
BF3·OEt2 couple can be replaced with a catalytic amount
(9)
(20)
(0.05 equiv) of Titanium(IV) Chloride. This system is highly ad-
HO
vantageous in chirality transfer from L-valine into a homoallylic
Al PbBr2
CHCl2
amine (diastereomeric ratio greater than 20:1) (eq 18).50
DMF, rt, 4.5 h
Cl
64%
Br
1. OH (10)
N CO2Me HN CO2Me
2.  e,  CO2
Al, TiCl4, rt
In the same way, a CF3CCl2 unit can be introduced into alde-
81%
77%
Ph Ph
hydes via a reaction with CF3CCl3. This process is chemospecific
NH2
and no adducts resulting from C F bond cleavage are formed.56
The Al PbBr2 system is also capable of mediating a facile
Ph (18)
reductive removal of bromine atoms from 6-bromo- and 6,6-
Similar to the transformations observed for acetals,46,47 intro- dibromopenicillanate derivatives (in MeOH/aq 1% HBr (9/1)),57
duction of TFA in the Al PbBr2 system allows reductive dimer- and has been used in prenylation reactions of p-benzoquinones
ization of N-alkylimines to vicinal diamines.51 and naphthoquinones.58
Reductive dimerization of allylic as well as benzylic bromides
is mediated by the Al PbBr2 system in DMF. In the case of allylic Aluminum Bismuth(III) Chloride. Al powder in combina-
bromides dimerization is complicated by allylic rearrangement tion with catalytic amounts of BiCl3 in aqueous THF at am-
and gives a mixture of isomeric 1,5-hexadienes. Benzylic bro- bient temperature promotes efficient Barbier-type allylation of
mides only give 1,2-diarylethanes.52 The same reactions are also aldehydes.59 The reaction occurs with allylic rearrangement in
induced by metallic Pb Bu4NBr in DMF.52 the entering unit and stereoselectively gives the erythro product.
An Al/PbBr2/NiCl2(bipy) (molar ratio 0.7:0.1:0.1) system pro- The reaction involves allylbismuth reagent formation through the
motes reductive dimerization of 2-arylvinyl halides to form 1,4- oxidative addition of an allylic halide to Bi0 generated by the re-
diaryl-1,3-butadienes, precursors of terphenyl derivatives (eq 19). duction of BiCl3 with Al. Metallic Bi is also capable of allylating
The process is almost stereospecific and both double bonds in aldehydes to homoallylic alcohols in aprotic DMF, but not in an
the dimer retain the C=C bond configuration of the starting vinyl aqueous solvent.60a Metallic Zn or Fe also can be used with BiCl3
halide. The reaction is carried out in DMF or MeOH at ambi- instead of Al.60b
ent temperature with KI (1.5 equiv) added. No dimerization is The system also induces alkylation of immonium cations. The
observed if THF, MeCN, CH2Cl2, or C6H6 are used as solvent procedure is experimentally simple due to its being performed
A list of General Abbreviations appears on the front Endpapers
ALUMINUM 5
in aqueous media.61 Among other alkylation agents, methyl and 10. (a) Albers, H.; Lange, S., Chem. Ber. 1952, 85, 278. (b) Schönnenberger,
H.; Thies, H.; Rappl, A., Arch. Pharm. (Weinheim, Ger.) 1965, 298, 635.
benzyl halides have been used for the first time in this Barbier
11. (a) Sugimoto, T.; Nishioka, N.; Murata, S.; Matsumura, S., Heterocycles
reaction system (eq 21).61b
1986, 24, 1565. (b) Sugimoto, T.; Nishioka, N.; Murata, S.; Matsumura,
N N
S., Heterocycles 1987, 26, 2091.
i-Pr2NH, CH2O MeI, Al BiCl3
N N
12. (a) Roedig, A.; Becker, H. J., Chem. Ber. 1956, 83, 906. (b) Roedig, A.;
THF H2O, rt
N N
Detzer, N.; Bonse, G., Justus Liebigs Ann. Chem. 1971, 752, 60.
H
N(i-Pr)2
13. Dyachenko, A. I.; Korneva, O. S.; Nefedov, O. M., Izv. Askad. Nauk
SSSR, Ser. Khim. 1980, 2842.
N(i-Pr)2 (21)
14. Riegger, P.; Steffen, K.-D., Chem.-Ztg. 1979, 103, 1.
78%
15. (a) Eisch, J. J. Comprehensive Organometallic Chemistry; Wilkinson,
G., Ed.; Pergamon: Oxford, 1982; Vol. 1, p 555. (b) Chen, J. G.; Beebe,
T. P., Jr.; Crowell, J. E.; Yates, J. T., Jr., J. Am. Chem. Soc. 1987, 109,
Aluminum Antimony(III) Chloride and Aluminum
1726. (c) Gaponik, L. V.; Mardykin, V. P., J. Gen. Chem. USSR (Engl.
Indium(III) Chloride. Both systems promote Barbier-type
Transl.) 1977, 47, 1448.
allylation of aldehydes. However, in contrast to InCl3, which is
16. (a) Halwachs, W; Schafari, K. A., Justus Liebigs Ann. Chem. 1859, 109,
256. (b) Grosse, A. W.; Mavity, J. M., J. Org. Chem. 1940, 5, 106.
required only in a catalytic amount for a reaction in aqueous
(c) Adkins, H.; Scanley, C., J. Am. Chem. Soc. 1951, 73, 2854.
THF,62 more than stoichiometric amounts of SbCl3 are used in
17. Wittenberg, D., Justus Liebigs Ann. Chem. 1962, 654, 23.
DMF H2O (3:1) and NaI is added to activate allylic bromides
18. (a) Nesmeyanov, A. N.; Sokolik, R. A. Methods of Elementoorganic
(aldehyde:allylic halide:Al:SbCl3:NaI = 1:1.2:2:1.5:1.2).63 Simi-
Chemistry; North-Holland: Amsterdam, 1967; Vol. 1, p 392. (b) Dolzine,
lar to the Al PbBr2 system,58 Al InCl3 also mediates prenylation
T. W.; Oliver, J. P., J. Am. Chem. Soc. 1974, 96, 1737.
of naphthoquinones.62 Al in combination with a catalytic amount
19. (a) Muetterties, E. L., J. Am. Chem. Soc. 1959, 81, 2597. (b) Ashby,
of SbCl3 induces acetalization of carbonyl compounds.63
E. S.; Foster, W. E., J. Am. Chem. Soc. 1962, 84, 3407.
20. (a) Kunai, A.; Kawakami, T.; Toyoda, E.; Ishikawa, M., Organometallics
Aluminum Nickel Alloy. In alkali medium this reagent is
1991, 10, 893. (b) Biran, C.; Bordeau, M.; Pons, P.; Leger, M.-P.;
employed for chemical reductions.64 Al affects liberation of hy-
Dunogues, J., J. Organomet. Chem. 1990, 382, C17. (c) Rösch, L., J.
drogen which actually plays the role of reducing agent (eq 22).
Organomet. Chem. 1976, 121, C15. (d) Voronkov, M. G.; Khudobin,
Y. I., Izv. Akad. Nauk SSSR, Ser. Khim. 1956, 713 (Chem. Abstr. 1957,
51, 1819f). (e) Dolgov, B N.; Kharitonov, N. P.; Voronkov, M. G., J.
NiAl + 3NaOH Ni + Na3AlO3 + 1.5 H2 (22)
Gen. Chem. USSR (Engl. Transl.) 1954, 24, 861 (Chem. Abstr. 1955, 49,
8094).
21. Seyferth, D.; Kahlen, N., J. Org. Chem. 1960, 25, 809.
Besides reduction of carbonyl compounds, organic halides, and
22. Komkov, I. P.; Karamanov, K. V.; Ivin, S. Z., J. Gen. Chem. USSR (Engl.
nitriles,64b in recent years numerous compounds containing N N
Transl.) 1958, 28, 2963 (Chem. Abstr. 1959, 53, 9053h).
and N O bonds (hydroxylamines, hydrazines, N-nitrosoamines,
23. (a) Demerseman, B.; Bouquet, G.; Bigorgne, M., J. Organomet. Chem.
N-oxides) have been reduced to amines.65 A few heterocycles are
1975, 101, C24. (b) Lindsell, W. E.; Parr, R. A., Polyhedron 1986, 5,
also reduced by this reagent, and high temperatures, high pres-
1259.
sures, or a hydrogen atmosphere are not required. Corresponding
24. (a) Troyanov, S. I.; Rybakov, V. B., Metalloorg. Khim. 1989, 2, 1382
tetrahydro derivatives are produced from pyridines, quinolines,
(Chem. Abstr. 1990, 113, 40 891z). (b) Troyanov, S. I.; Rybakov, V.
and pyrazines, whereas pyrimidines, pyridazines, oxazoles, and
B., Metalloorg. Khim. 1992, 5, 1082 (Chem. Abstr. 1993, 118, 191
isoxazoles undergo reductive cleavage of C N, N N, or N O
897k).
bonds to yield saturated diamines or diamino alcohols (see Raney
25. Wang, W. B.; Shi, L.-L.; Huang, Y.-Z., Tetrahedron Lett. 1990, 31, 1185.
Nickel).66
26. Brieger, G.; Watson, S. W.; Barav, D. G.; Shene, A. L., J. Org. Chem.
1979, 44, 1340.
27. Mitchell, P. W. D., Org. Prep. Proced. Int. 1990, 22, 534.
28. Laan, J. A. M.; Ward, J. P., Chem. Ind. (London) 1987, 34.
1. Smith, M. Reduction Techniques and Applications in Organic Synthesis;
29. (a) Stroh, R.; Ebersberger, J.; Haberland, H.; Hahn, W., Angew. Chem.
Augustine, R. L., Ed.; Dekker: New York, 1968; p 95.
1957, 69, 124. (b) Ecke, G. G.; Napolitano, J. P.; Filbey, A. H.; Kolka,
2. (a) Lehmkuhl, H.; Ziegler, K., Methoden Org. Chem. (Honben-Weyl)
A. J., J. Org. Chem. 1957, 22, 639.
1970, XIII/4, 168. (b) Ziegler, K.; Gellert, H. G., Lehmkuhl, H.; Pfohl,
30. Skell, P. S.; Wolf, L. R., J. Am. Chem. Soc. 1972, 94, 7919.
W.; Zosel, K., Justus Liebigs Ann. Chem. 1960, 629, 1.
31. Barbot, F., Bull. Soc. Chem. Fr. Part 2 1984, 83.
3. Sarmah, B. K.; Barua, N. C., Tetrahedron 1991, 47, 8587.
32. (a) Schneider, D. F.; Weedon, B. C. L., J. Chem. Soc. (C) 1967, 1686.
4. Berlan, J.; Sztajnbok, P.; Besace, Y.; Cresson, P., C. R. Hebd. Seances
(b) Eiter, K.; Oediger, H., Justus Liebigs Ann. Chem. 1965, 682, 62.
Acad. Sci., Ser. C 1985, 301, 693.
33. (a) Kalbe, H.-J.; Truscheit, E.; Eiter, K., Justus Liebigs Ann. Chem. 1965,
5. Braun, W.; Mecke, R., Chem. Ber. 1966, 99, 1991.
684, 14. (b) Barbot, F.; Miginiac, Ph., J. Organomet. Chem. 1986, 304,
83.
6. Altman, Y.; Ginsburg, D., J. Chem. Soc. 1959, 466.
34. Picotin, G.; Miginiac, Ph., Chem. Ber. 1986, 119, 1725.
7. (a) Silberg, A.; Benkö, A., Chem. Ber. 1964, 97, 1915. (b) Leitch, L. C.;
Moorse, A. T., Can. J. Chem. 1953, 31, 785.
35. Guedin-Vuong, D.; Nakatani, Y., Bull. Soc. Chem. Fr. Part 2 1986, 245.
8. Christmann, O., Justus Liebigs Ann. Chem. 1968, 716, 147. 36. Ganem, B., Tetrahedron Lett. 1971, 4105.
9. (a) Floru, L.; Sanielevici, H.; Stoicescu, C.; Comaneanu, M., Rev. Roum. 37. (a) Nokami, J.; Otera, J.; Sudo, T.; Okawara, R., Organometallics 1983,
Chem. 1961, 12, 649 (Chem. Abstr. 1955, 49, 6858F). (b) Iida, H.; Fuse, 2, 191. (b) Mandai, T.; Nokami, J.; Yano, T.; Yoshinaga, Y.; Otera, J., J.
S., J. Chem. Soc. Jpn., Ind. Chem. Sect. 1953, 56, 964 (Chem. Abstr. Org. Chem. 1984, 49, 172. (c) Nokami, J.; Wakabayashi, S.; Okawara,
1962, 57, 14 985i). R., Chem. Lett. 1984, 869.
Avoid Skin Contact with All Reagents
6 ALUMINUM
38. Uneyama, K.; Kamaki, N.; Moriya, A.; Torii, S., J. Org. Chem. 1985, 53. Tanaka, H.; Kosaka, A.; Yamashita, S.; Morisaki, K.; Torii, S.,
50, 5396. Tetrahedron Lett. 1989, 30, 1261.
39. (a) Mukaiyama, T.; Harada, T., Chem. Lett. 1981, 1527. (b) Mukaiyama, 54. Tanaka, H.; Yamashita, S.; Yamanoue, M.; Torii, S., J. Org. Chem. 1989,
T.; Harada, T.; Shoda, S., Chem. Lett. 1980, 1507. (c) Uneyama, K.; 54, 444.
Matsuda, H.; Torii, S., Tetrahedron Lett. 1984, 25, 6017.
55. Torii, S.; Tanaka, H.; Yamashita, S.; Yamanoue, M.; Tanigushi, M.;
40. (a) Nokami, J.; Tamaoka, T.; Ogawa, H.; Wakabayashi, S., Chem. Lett. Sasaoka, M., Chem. Express 1987, 2, 615.
1986, 541. (b) Drewes, S. E.; Hoole, R. F. A., Synth. Commun. 1985, 15,
56. Tanaka, H.; Yamashita, S.; Katayama, Y.; Torii, S., Chem. Lett. 1986,
1067.
2043.
41. (a) Coxon, J. M.; van Eyk, S. J.; Steel, P. J., Tetrahedron 1989, 45,
57. Tanaka, H.; Tanaka, M.; Nakai, A.; Katayama, Y.; Torii, S., Bull. Chem.
1029. (b) Uneyama, K.; Nanbu, H.; Torii, S., Tetrahedron Lett. 1986, 27,
Soc. Jpn. 1989, 62, 627.
2395.
58. Khanna, R. N.; Singh, P. K., Synth. Commun. 1990, 20, 1743.
42. Yang, Z.-Y.; Burton, D. J., J. Org. Chem. 1991, 56, 1037.
59. Wada, M.; Okhi, H.; Akiba, K.-Y., J. Chem. Soc., Chem. Commun. 1987,
43. Tanaka, H.; Yamashita, S.; Hamatani, T.; Ikemoto, Y.; Torii, S., Synth.
708.
Commun. 1987, 17, 789.
60. (a) Wada, M.; Akiba, K.-y., Tetrahedron Lett. 1985, 26, 4211. (b) Wada,
44. Tanaka, H.; Yamashita, S.; Hamatani, T.; Ikemoto, Y.; Torii, S., Chem.
M.; Okhi, H.; Akiba, K. Tetrahedron Lett. 1986, 27, 4771.
Lett. 1986, 1611.
61. (a) Katritzky, A. R.; Shobana, N.; Harris, P. A. Tetrahedron Lett. 1991, 32,
45. Tanaka, H.; Yamagushi, T.; Tanigushi, M.; Komeyama, Y.; Sasaoka, M.;
4247. (b) Katritzky, A. R.; Shobana, N.; Harris, P. A., Organometallics
Shiroi, T.; Torii, S., Chem. Express 1991, 6, 435.
1992, 11, 1381.
46. Tanaka, H.; Yamashita, S.; Ikemoto, Y.; Torii, S., Tetrahedron Lett. 1988,
62. Araki, S.; Jin, S.-J.; Idou, Y.; Butsugan, Y., Bull. Chem. Soc. Jpn. 1992,
29, 1721.
65, 1736.
47. Dhimane, H.; Tanaka, H.; Torii, S., Bull. Soc. Chem. Fr. Part 2 1990,
63. Wang, W. B.; Shi, L.-L.; Huang, Y.-Z., Tetrahedron 1990, 46, 3315.
283.
64. (a) Papa, D.; Schwenk, E.; Whitman, B., J. Org. Chem. 1942, 7, 587.
48. Tanaka, H.; Yamashita, S.; Ikemoto, Y.; Torii, S., Chem. Lett. 1987, 673.
(b) Fieser & Fieser 1967, 1, 718.
49. Tanaka, H.; Nakahara, T.; Dhimane, H.; Torii, S., Tetrahedron Lett. 1989,
65. Lunn, G.; Sansone, E. B.; Keefer, L. K., Synthesis 1985, 1104.
30, 4161.
66. (a) Lunn, G.; Sansone, E. B., J. Org. Chem. 1986, 51, 513. (b) Lunn, G.,
50. Tanaka, H.; Inoue, K.; Pokorski, U.; Taniguchi, M.; Torii, S., Tetrahedron
J. Org. Chem. 1987, 52, 1043. (c) Saavedra, J. E., Org. Prep. Proced.
Lett. 1990, 31, 3023.
Int. 1985, 17, 155.
51. Tanaka, H.; Dhimane, H.; Fujita, H.; Ikemoto, Y.; Torii, S., Tetrahedron
Lett. 1988, 29, 3811.
Emmanuil I. Troyansky
52. Tanaka, H.; Yamashita, S.; Torii, S., Bull. Chem. Soc. Jpn. 1987, 60,
Institute of Organic Chemistry, Moscow, Russia
1951.
A list of General Abbreviations appears on the front Endpapers