An expedient approach to ferrocenyl thioamides via Fischer carbenes

Oxidative demetalation of Fischer ferrocenyl ethoxy carbene complexes (1a–c, M = Cr, Mo, W) and new Fischer ferrocenyl R-amino carbene complexes [2–5 (a–c), 11–15 (a–c), and 21–22 (a–c); M = Cr, Mo, W; R = H, CH3, C2H5, C3H7, (CH2)2OH, (CH2)3OH, (CH2)2(OMe)2, (CH2)3N(Me)2, CH2CHdouble bond; length as m-dashCH2, (CH2)2OSi(CH3)3, (CH2)3OSi(CH3)3] with elemental sulfur–NaBH4 were carried out under mild conditions, obtaining O-ethyl ferrocenecarbothioate (6) and novel ferrocenyl thioamides (7–10 and 16–20) in excellent yields.