The origin of diastereoselectivity in cyclopropanation reactions of the iron carbene complex [(η5-C5H5)(CO)2FeCH[(η6-o-CH3OC6H4)Cr(CO)3]]+
作者:Qinwei Wang、M.Mahmun Hossain
DOI:10.1016/s0022-328x(00)00731-2
日期:2001.1
The origin of diastereoselectivity in cyclopropanation reactions of the iron carbene complex [(η5-C5H5)(CO)2FeCH[(η6-o-CH3OC6H4)Cr(CO)3]]+ has been investigated. The chromium participation has been proved by the upfield shifts of both 1H- and 13C-NMR for CαH and Cα, which stabilized the iron carbene and may result in a late transition-state for the cyclopropanation reaction via tricarbonylchromium-complexed
非对映选择性的在铁卡宾络合物[(η的环丙烷化反应中的原点5 -C 5 H ^ 5)(CO)2 FeCH[(η 6 - ö -CH 3 OC 6 H ^ 4的Cr(CO))3 ] +已被调查。铬参与已被证明通过两者的高场位移1 H-和13 C-NMR对C α ħ和C α,它稳定了卡宾铁,并可能通过三羰基铬络合的卡宾铁而导致环丙烷化反应的后期过渡态。因此,期望反式选择性。然而,当使用芳族烯烃时,在过渡态期间可能存在π堆积效应,从而导致环丙烷化的顺式选择性。