FLP-CO2 adducts: convenient sources of frustrated Lewis pairs for stoichiometric and catalytic chemistry.

The compounds [tBu3PCO2B(C6F5)3] 1 and [TMPH][C5H6Me4NCO2B(C6F5)3] 7 are easily handled synthons releasing CO2 on warming generating the corresponding FLPs which can activate H2, disulfides, alkynes, silanes and phenols. Compound 7 was also shown to be an effective FLP catalyst precursor for the hydrogenation and hydrosilylation of imines, electron deficient olefins, and ketones while less effective for electron-rich olefins. The advantages and limitations of this approach are considered.