The UM06-2X/aug-cc-pVTZ//UM06-2X/6-311G(d) theoretical models of representative singlet trans-2′-substituted cyclobutylcarbenes were computed. The :CH-group of carbenes with an ERG is bent toward the c-C₄H₇-ring’s proximal C1′–C2′ single bond. The :CH-group of carbenes with an EWG is bent toward the c-C₄H₇-ring’s distal C1′–C4′ single bond. The contrasting stereoelectronic effect was computationally tested using trimethylsilyl vs. bromo substituents to determine if exo-1- and exo-2-substituted bicyclo[2.1.0]pentanes would be produced in diastereomeric excess.

中文翻译：

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非对映选择性碳烯：弯曲单线态反式-2'-取代的环丁基卡宾的立体电子控制

计算了代表性单重态反式-2'-取代的环丁基卡宾的UM06-2X / aug-cc-pVTZ // UM06-2X / 6-311G（d）理论模型。的： CH-基与ERG卡宾是向弯曲Ç -C ₄ ħ ₇形环的近侧C1'-C2'单键。的： CH-组以EWG卡宾是向弯曲Ç -C ₄ ħ ₇形环的远侧C1'-C4'单键。使用三甲基甲硅烷基与溴取代基计算对比了立体电子效应，以确定exo -1-和exo-2-取代的双环[2.1.0]戊烷将以非对映异构体过量的形式产生。