The Fukuyama reduction is an organic reaction and an

organic reduction Organic reductions or organic oxidations or organic redox reactions are redox reactions that take place with organic compounds. In organic chemistry oxidations and reductions are different from ordinary redox reactions, because many reactions car ...

in which a

thioester In organic chemistry, thioesters are organosulfur compounds with the functional group . They are analogous to carboxylate esters () with the sulfur in the thioester playing the role of the linking oxygen in the carboxylate ester, as implied by t ...

is reduced to an

aldehyde In organic chemistry, an aldehyde () is an organic compound containing a functional group with the structure . The functional group itself (without the "R" side chain) can be referred to as an aldehyde but can also be classified as a formyl grou ...

by a silyl hydride in presence of a

catalytic Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recyc ...

amount of

palladium Palladium is a chemical element with the symbol Pd and atomic number 46. It is a rare and lustrous silvery-white metal discovered in 1803 by the English chemist William Hyde Wollaston. He named it after the asteroid Pallas, which was itself na ...

. This reaction was invented in 1990 by

Tohru Fukuyama is a Japanese organic chemist and Professor of Chemistry at University of Tokyo in Japan. He discovered the Fukuyama coupling in 1998. Biography Fukuyama studied chemistry at Nagoya University with degrees Bachelor's (1971) and Master's (1973) d ...

. In the original scope of the reaction the silyl hydride was

triethylsilane Triethylsilane is the organosilicon compound with the formula (C2H5)3SiH. It is a trialkylsilane. The Si-H bond is reactive. This colorless liquid is used in organic synthesis as a reducing agent and as a precursor to silyl ethers. As one of th ...

and the catalyst

palladium on carbon Palladium on carbon, often referred to as Pd/C, is a form of palladium used as a catalyst. The metal is supported on activated carbon to maximize its surface area and activity. Uses Hydrogenation Palladium on carbon is used for catalytic hydrog ...

: :

Fukuyama reductions are used for the conversion of carboxylic acids (as thioester precursor) to aldehydes which is considered a difficult procedure because of the ease of secondary reduction to an alcohol.

Reaction mechanism

The basic reaction mechanism for this reaction takes place as a

catalytic cycle In chemistry, a catalytic cycle is 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, bioinorganic chemistry, materials s ...

: *

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. Oxid ...

: *: + Pd^0 -> RC(O)-Pd^-SR *

Transmetallation Transmetalation (alt. spelling: transmetallation) is a type of organometallic reaction that involves the transfer of ligands from one metal to another. It has the general form: :M1–R + M2–R′ → M1–R′ + M2–R where R and R′ can be, but ...

: *: + R3SiH -> + R3Si-SR *

Reductive elimination Reductive elimination is an elementary step in organometallic chemistry in which the oxidation state of the metal center decreases while forming a new covalent bond between two ligands. It is the microscopic reverse of oxidative addition, and is ...

: *: RC(O)-Pd^-H -> + Pd^0

Scope

In a variation of the Fukuyama reduction the core

BODIPY BODIPY is the technical common name of a chemical compound with formula , whose molecule consists of a boron difluoride group joined to a dipyrromethene group ; specifically, the compound 4,4-difluoro-4-bora-3a,4a-diaza-''s''-indacene in the ...

molecule has been synthesized from the SMe-substituted derivative:''The Smallest and One of the Brightest. Efficient Preparation and Optical Description of the Parent Borondipyrromethene System.'' I. J. Arroyo, R. Hu, G. Merino, B. Z. Tang, E. Peña-Cabrera
''J. Org. Chem.'' 2009, ASAP
Additional reagents are copper(I)-thiophene-2-carboxylate (CuTC), Pd(dba)2 and tri(2-furyl)phosphine : BODIPY synthesis Arroyo 2009

In the related Fukuyama coupling the hydride is replaced by a

carbon nucleophile In organic chemistry, a carbanion is an anion in which carbon is trivalent (forms three bonds) and bears a formal negative charge (in at least one significant resonance form). Formally, a carbanion is the conjugate base of a carbon acid: :R3CH ...

References

{{Organic reactions Organic reduction reactions Name reactions