Chromium-Templated Benzannulation of (η5-Cyclohexadienyl)Mn(CO)3-Methoxy-Cr(CO)5 Carbenes

Pentacarbonyl­{methoxy-[1-(η5-4-methoxy-6-phenylcyclohexadienyl)­tricarbonylmanganese]­carbene}­chromium
(5) accessible from (η5-1-bromo-4-methoxy-6-phenylcyclohexadienyl)­tricarbonylmanganese
(4) and Cr­(CO)6 undergoes a chromium-templated
benzannulation with 3-hexyne to give monometallic Cr complex 12 in 60% yield. The key feature of this reaction is the participation
of a conjugated double bond of the η5-cyclohexadienyl-Mn
moiety in the [3+2+1] benzannulation reaction. The X-ray structure
of complex 12 reveals a syn position
of the phenyl group with respect to the Cr tripod, supporting the
participation of the Mn moiety in the benzannulation process.

五羰基{[亚甲氧基-1-(η5-4-甲氧基-6-苯基环己二烯基)三羰基锰]碳烯}铬(5)可通过(η5-1-溴-4-甲氧基-6-苯基环己二烯基)三羰基锰(4)与Cr(CO)6反应，在铬模板引导下，与3-己炔进行苯并化反应，以60%的产率得到单金属铬配合物12。该反应的关键特征在于η5-环己二烯基-Mn基团共轭双键参与了[3+2+1]苯并化反应。配合物12的X射线结构显示，苯基相对于铬三脚架处于同位，这证实了Mn基团在苯并化过程中的参与。