Platinum-Catalyzed Alkene Cyclohydroamination: Evaluating the Utility of Bidentate P,N/P,P Ligation and Phosphine-Free Catalyst Systems

The efficacy of phosphine-free Pt precatalysts including PtCl2 and (COD)PtCl2 in promoting the cyclohydroamination of primary as well as secondary alkyl/arylamines tethered to α-olefins is demonstrated for the first time. Further catalytic studies examining the use of phenylene-P,N co-ligands, as well as neutral, cationic, and formally zwitterionic complexes derived from the new ligand precursor 1-PPh2-2-P(tBu)2-indene, revealed comparable reactivity in Pt-catalyzed cyclohydroamination catalysis relative to these phosphine-free catalysts.