Hydrogen auto-transfer

As borrowing hydrogen processes avoid manipulations otherwise required for discrete alcohol oxidation and the use of stoichiometric organometallic reagents, they typically display high levels of atom-economy and, hence, are viewed as examples of Green chemistry.

Application of the Guerbet reaction to the development of ethanol-to-butanol processes has garnered interest as a method for the production of renewable fuels.

The first hydrogen auto-transfer processes that convert primary alcohols to products of carbonyl addition were reported by Michael J. Krische in 2007-2008 using homogenous iridium and ruthenium catalysts.

[18] The formation of carbon–carbon bonds have been achieved through borrowing hydrogen-type indirect Wittig,[19] aldol,[20] Knoevenagel condensations [21] and also through various carbon nucleophiles.

[22][23] Related to the Guerbet reaction, Donohoe and coworkers have developed enantioselective borrowing hydrogen-type enolate alkylations.