The Fukuyama reduction is an organic reaction

Organic reaction

Organic reactions are chemical reactions involving organic compounds. The basic organic chemistry reaction types are addition reactions, elimination reactions, substitution reactions, pericyclic reactions, rearrangement reactions, photochemical reactions and redox reactions. In organic synthesis,...

 and an organic reduction in which a thioester

Thioester

Thioesters are compounds with the functional group C-S-CO-C. They are the product of esterification between a carboxylic acid and a thiol. Thioesters are widespread in biochemistry, the best-known derivative being acetyl-CoA.-Synthesis:...

 is reduced to an aldehyde

Aldehyde

An aldehyde is an organic compound containing a formyl group. This functional group, with the structure R-CHO, consists of a carbonyl center bonded to hydrogen and an R group....

 by a silyl hydride

Silyl hydride

Silicon hydrides are chemical compounds which contain a silicon–hydrogen bond. The silicon-to-hydrogen bond is longer than the C–H bond and weaker . Hydrogen is more electronegative than silicon hence the naming convention of silyl hydrides. The parent compound SiH4 is called silane, and an...

 in presence of a catalytic amount of palladium

Palladium

Palladium is a chemical element with the chemical symbol Pd and an atomic number of 46. It is a rare and lustrous silvery-white metal discovered in 1803 by William Hyde Wollaston. He named it after the asteroid Pallas, which was itself named after the epithet of the Greek goddess Athena, acquired...

. This reaction was invented in 1990 by Tohru Fukuyama. In the original scope of the reaction the silyl hydride was triethylsilyl hydride and the catalyst palladium on carbon

Palladium on carbon

Palladium on carbon, often referred to as Pd/C, is a form of palladium used for catalysis. It is usually used for catalytic hydrogenations in organic chemistry...

:

Fukuyama reductions are used for the conversion of carboxylic acid

Carboxylic acid

Carboxylic acids are organic acids characterized by the presence of at least one carboxyl group. The general formula of a carboxylic acid is R-COOH, where R is some monovalent functional group...

s (as thioester precursor) to aldehydes which is considered a difficult procedure because of the ease of secondary reduction to an alcohol

Alcohol

In chemistry, an alcohol is an organic compound in which the hydroxy functional group is bound to a carbon atom. In particular, this carbon center should be saturated, having single bonds to three other atoms....

.

Reaction mechanism

The basic reaction mechanism

Reaction mechanism

In chemistry, a reaction mechanism is the step by step sequence of elementary reactions by which overall chemical change occurs.Although only the net chemical change is directly observable for most chemical reactions, experiments can often be designed that suggest the possible sequence of steps in...

 for this reaction takes place as a catalytic cycle

Catalytic cycle

A catalytic cycle in chemistry is a term for a multistep reaction mechanism that involves a catalyst . The catalytic cycle is the main method for describing the role of catalysts in biochemistry, organometallic chemistry, materials science, etc. Often such cycles show the conversion of a...

:

• Oxidative addition
  Oxidative addition
  Oxidative addition and reductive elimination are two important and related classes of reactions in organometallic chemistry. Oxidative addition is a process that increases both the oxidation state and coordination number of a metal centre...
  
  :

R-C(O)-SR + Pd(0) → RC(O)-Pd(II)-SR

• Transmetallation:

RC(O)-Pd(II)-SR + R₃SiH → RC(O)-Pd(II)-H + R₃Si-SR

• Reductive elimination:

RC(O)-Pd(II)-H → RC(O)-H + Pd(0)

Scope

In a variation of the Fukuyama reduction the core BODIPY

BODIPY

BODIPY, short for boron-dipyrromethene, is a class of fluorescent dyes. It is composed of dipyrromethene complexed with a disubstituted boron atom, typically a BF2 unit. The IUPAC name for the BODIPY core is 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene...

 molecule has been synthesized from the SMe-substituted derivative :

In the related Fukuyama coupling

Fukuyama coupling

The Fukuyama coupling is a coupling reaction taking place between a thioester and an organozinc halide in the presence of a palladium catalyst. The reaction product is a ketone. This reaction was discovered by Tohru Fukuyama et al. in 1998...

 the hydride is replaced by a carbon nucleophile.