Different Reactivities of Alkoxy- and Thiocarbene Complexes of Fischer-Type: Formation of (N-Enamino)ethoxycarbene Complexes and Quinolines, Respectively

Abstract

Alkoxy-and thiocarbene complexes of chromium and tungsten afford different type of products on reaction with (N-aryl)imidoyl chlorides. The (n-butyl)ethoxycarbene complex [(OC) 5 WdC(OEt)n-Bu] and (N-aryl)imidoyl chlorides t-BuClCdNC 6 H 4 R 4 (R 4 = H, OMe) undergo a rearrangement to (N-enamino)ethoxycarbene complexes, whereas quinolines are obtained from the corresponding reaction of (alkyl)thiocarbene complexes [(OC) 5 MdC(SEt)CH 2 R] (M = W, Cr; R = n-Pr, Me) with (N-aryl)imidoyl chlorides R

Photochemical Alkyne Insertions into the Iron–Thiocarbonyl Bond of [Fe2(CS)(CO)3(Cp)2]

“…As evidenced in the discussion of the structural data, the Fe–C 1 interaction in 4a , b has some metal–carbene character. Like classic Fischer alkoxycarbenes, thiocarbene complexes are expected to react with nucleophiles, with some differences due to the nature of the heteroatoms . For example, the iron complex [FeCp­(CO) 2 (CHSMe)] + is known to undergo nucleophilic addition by a variety of nucleophiles, and the overall positive charge of the complex certainly contributes to enhance its reactivity .…”