Abstract
Synthesis of the new molybdenum η 4 -trimethylene cationic complex CpMo(CO) 2 (η 4 -MeC 4 H 5 )BF 4 (4) has been described. Deprotonation of 4 gives CpMo(CO) 2 (η 3 -2-vinylallyl), which undergoes an unusual cyclization with TCNE and PhCHO (BF 3 catalyzed) to afford six-membered-ring products. The molecular structure of a bicyclic product based on this cyclization has been described. © 1991 American Chemical Society.