Carbon Dioxide Insertion by a Methylene‐Bridged Ga/P FLP

The geminal methylene‐bridged frustrated Lewis pair Bis 2 Ga–CH 2 –P t Bu 2 ( 1 , Bis = CH(SiMe 3 ) 2 ) was synthesized by reacting Bis 2 GaBr with LiCH 2 P t Bu 2 and its behavior toward small molecules was investigated. Unlike its oxygen‐bridged analog, Bis 2 Ga–O–P t Bu 2 , it does not react with hydrogen gas and decomposes under SO 2 atmosphere; however, similar 1,2‐addition products of 1 with carbon dioxide, carbon disulfide and cis‐ azobenzene were obtained. Strikingly, the CO 2 adduct undergoes a rearrangement at higher temperatures, with an insertion of the CO 2 unit into the GaCH 2 bond, leading to a gallium carboxylate. All compounds were characterized using multinuclear NMR spectroscopy, elemental analysis, and X‐ray diffraction measurements.