Fulvene formation on attempted protection of a C-2 symmetric ferrocenyl bisphosphine as its sulfide

Attempted protection of the phosphines in the C-2 symmetric ferrocene, 1,1' -bis[(S)-4-isopropyloxazolin-2-yl]-2,2'-diphenylphosphinoferrocene, as thei r sulfides failed to give the desired product. Fragmentation of the, typica lly stable, ferrocene system occurred with the phosphine substituted fulven e, 5-[(4S)-4-isopropyl-1,3-oxazolan-2-yliden]-1,3-cyclopentadienyl (dipheny l)phosphine sulfide, being isolated. (C) 1999 Elsevier Science Ltd. All rig hts reserved.