formation of a product (16) that contains an annelated five-membered borata heterocycle at the Cp ring. This is probably formed by means of a reaction sequence involving regioselective hydroboration, followed by an electrophilic substitution reaction at the Cp ring by the strongly Lewis acidic –B(C6F5)2 group, in which the iridium metal base acts as the proton abstractor. Products 13 and 16 were characterized
用(烯丙基)
环戊二烯酸
锂处理(cod)IrCl二聚体得到(
C5H4–
CH2–CH= )Ir(cod)(11)。在 100 °C 时,11 完全异构化为其环共轭(反式
CH3–CH=CH– )Ir(cod) 异构体 (13)。随后添加 HB(
C6F5)2 导致产物 (16) 的形成,该产物在 Cp 环处包含一个退火的五元
硼砂杂环。这可能是通过涉及区域选择性
硼氢化的反应序列形成的,然后是强
路易斯酸性-B( )2 基团在 Cp 环上的亲电取代反应,其中
铱金属碱充当质子提取剂。产物13和16通过X射线衍射表征。(© Wiley-
VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)