各种还原剂的还原能力
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Function Reagent Aldehydes
& Ketones
Carboxylic
Acids
Carboxylic
Esters
Acyl
Chlorides
Amides Nitriles
H2
& catalyst
alcohols
( slow, Pt, Pd )
(v. slow) (v. slow)
aldehydes
( Pd/BaSO4 )
(v. slow)
amines
( Ni cat. )
NaBH4 polar solvent alcohols N.R.
alcohols
(slow)
complex
mixture
N.R. N.R.
LiAlH4
ether or THF
alcohols 1º-alcohol alcohols 1º-alcohol amines 1º-amine
LiAlH(Ot-Bu)3 1 eq. in THF
alcohols
(slow at 0º)
N.R. v. slow
aldehyde
(-78 º C)
aldehyde
(-78 º C)
aldehyde
(0 º C)
(iso-Bu)2AlH 1 eq. in toluene alcohols 1º-alcohol
aldehyde
(-78º C)
1º-alcohol
aldehyde
(-78 º C)
aldehyde
(-78 º C)
B2H6 THF alcohols
(slow)
1º-alcohol (v. slow)
complex
mixture
1º-amine 1º-amine
Color Code
Reduction occurs readily under normal conditions of temperature and pressure.
Reduction occurs readily, but selectivity requires low temperature.
Slow reduction occurs. Heating and/or high pressures of hydrogen are needed for effective use. Reduction occurs very slowly or not at all (N.R.).
LiAlH(Ot-Bu)3 是比LiAlH4更加温和的还原剂，近似于硼氢化钠，可以还原醛酮酰氯，不还原脂肪酸酯和腈，但可以还原脂肪酸以及脂肪酸的苯酯。还原四氢呋喃开环。还原能力顺序如下：
LiAlH4 > LiAlH(OMe)3 > LiAlH(O-t-Bu)3 > NaBH4