# C,N‐Chelated Organogermanium(II) Hydride as Catalyst for Esterification of Aldehydes

## TL;DR

A new organogermanium compound was found to effectively catalyze the esterification of aldehydes into t-butyl esters.

## Contribution

A C,N-chelated organogermanium(II) hydride was identified as a novel catalyst for aldehyde esterification.

## Key findings

- The organogermanium compound catalyzed esterification of aldehydes using potassium alkoxides.
- t-Butyl esters of carboxylic acids were confirmed via GC-MS analysis.
- Mechanistic insights were obtained through DFT calculations and NMR/IR spectroscopy.

## Abstract

The reactions of the monomeric C,N‐chelated organogermanium(II) hydride L(H)Ge·BH3 (1) with potassium alkoxides KOR provided potassium hydrido‐alkoxo‐germanato‐borates {K(THF)2[BH3·Ge(L)(H)(OR)]}2 (R = 
t
Bu (2), C(CH3)2CH2CH3 (3)) as products of KOR addition. Compounds 2 and 3 react with benzaldehyde under formation of alkyl esters of benzoic acid along with elimination of a neutral complex L(H)Ge·BH3 (1). Thus complex 1 was tested as a useful catalyst for esterification of aldehydes by KO
t
Bu. The GC‐MS analysis revealed formation of t‐butyl esters of appropriated carboxylic acids. The mechanistic studies for the esterification of benzaldehyde with KO
t
Bu catalyzed by 1 were also performed either theoretically (DFT calculations), or experimentally (NMR and IR spectroscopy).

Monomeric C,N‐chelated organogermanium(II) hydride L(H)Ge·BH3 (1) reacts with potassium alkoxides to give potassium hydrido‐alkoxo‐germanato‐borates {K(THF)2[BH3·Ge(L)(H)(OR)]}2 (R = 
t
Bu (2), C(CH3)2CH2CH3 (3)) as products of KOR addition. Moreover, complex 1 was tested as useful catalyst for esterification of aldehydes by KO
t
Bu to yield t‐butyl esters of appropriated carboxylic acids.