Revisit of the leaving group (LG)/halogen exchange in 1,2-dimesityl-2-phenylvinyl-LG systems: a caveat about ‘mistaken identity’ by X-ray diffraction
作者:Hatim Salim、Xin Chen、Zvi Rappoport
DOI:10.1002/poc.430
日期:2001.11
reactions of Z-4-OH with SOCl2, PBr3 or POBr3 proceed via initial formation of chlorosulfite or phosphorus-containing ester leaving groups that solvolyze to 2 or its ion pair, which react with halide ions formed from the anionic leaving group to give Z-4-X (X = Cl, Br). From the X-ray data of MesC(Ph) = C(X)Mes, (X = Br, OAc, E and Z isomers; X = OTs, Cl, I, Z isomer; X = H, E isomer) the effect of X on
Z -1,2-二甲硅烷基-2-苯基乙烯醇(Z -4-OH)与POBr 3一起提供的不寻常报道重新研究了晶体学上鉴定为E -1,2-二甲硅烷基-2-苯基乙烯基溴(E -4-Br)以及相关的反应。的反应ž -4-OH用甲苯磺酰氯,得到Ž -4-OT S,ž -4-CL用的SOCl 2和ž -4-溴与我3的SiCl /溴化锂,PBR 3或PPH 3 /溴2。反应ž -4-OT s的溴-或I -中的MeCN得到Ž -4-溴或ž --4我分别。的反应ž -4-OH用POBr 3几个条件下重复并给ž -4-溴,将其鉴定X射线衍射。与先前实验的差异归因于在Z -4-Br主体中形成了微量的E -4-Br,并通过X射线衍射分析了E -4-Br的晶体。泛化该MESC(PH)= C * -Mes(* =·或+)物种捕获试剂(例如溴- ,我−证实并延长了带有β-间苯二甲环的面部的* = +)。有人建议的反应Ž -4-OH用的SOCl