THE INFERIOR P-DONOR ABILITY OF PHOSPHANYL VERSUS AMINO SUBSTITUENTS - CONSEQUENCES ON THE STABILITY AND REACTIVITY OF PHOSPHANYLCARBENE AND AMINOCARBENE

Bis(diisopropylamino) (trimethylstannyl)phosphane (2) reacts with the (chloromethylene)diisopropylammonium salt 1 affording the C-phosphanyl -substituted iminium salt 3 (67 % yield), which features a short C-N ( 1.284 Angstrom) and a long P-C bond (1.850 Angstrom), a planar iminium nitrogen atom and a pyramidalized phosphorus atom. Deprotonation of 3 leads to the enamine 8 (92 % yield), while addition of sodium methoxi de followed by thermolysis of the resulting hemiaminal 9 (90 % yield) gives rise to the azaphosphetane 10 (85 % yield), by intramolecular CH insertion of the transiently formed (amino)(phosphanyl)carbene 6.