Deoxygenative CO2 conversions with triphenylborane and phenylsilane in the presence of secondary amines or nitrogen-containing aromatics.

BPh₃ catalyzed the N-methylation of secondary amines and the C-methylenation (methylene-bridge formation between aromatic rings) of N,N-dimethylanilines or 1-methylindoles in the presence of CO₂ (1 atm) and PhSiH₃ without solvent at 30–40 °C. A cascade reaction from 1-methyl-2-oxindole to 3,3′-methylenebis(1-methylindole) via 1-methylindole also proceeded. [ABSTRACT FROM AUTHOR]