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)(2)OH, (CH2)(3)OH, (CH2)(2)(OMe)(2), (CH2)(3)N(Me)(2), CH2CH=CH2, (CH2)(2)OSi(CH3)(3), (CH2)(3)OSi(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. (C) 2009 Elsevier B.V. All rights reserved.