Ring-fused <i>gem</i>-Dibromocyclopropanes as Precursors to "Tunable" Molecular Clefts Possessing Convergent Functional Groups
作者:Martin Banwell、Robert Gable、Richard Greenwood、John Lambert、Maureen Mackay、Justine Walter
DOI:10.1055/s-1997-933
日期:1997.8
Reaction of certain ring-fused gem-dibromocyclopropanes with methyllithium affords syn-cyclopropylidene dimers such as 2 which contain converging and potentially co-ordinating groups. Cyclofunctionalisation of the double bonds within these latter compounds allows the "angle-of-bite" between the co-ordinating groups to be "tuned" such that, under electrospray conditions in the mass spectrometer, derivative 7 forms a 1:1:1 complex with, for example, D-ribose and sodium ion.
Stereoconvergent Generation of a Contrasteric<i>syn</i>-Bicyclopropylidene (=<i>syn</i>-Cyclopropylidenecyclopropane) by<i>Stille</i>-Like Coupling
作者:Murat Güney、Selçuk Eşsiz、Arif Daştan、Metin Balci、Ottorino De Lucchi、Ertan Şahin、Fabrizio Fabris
DOI:10.1002/hlca.201200291
日期:2013.5
CS‐symmetric bicyclopropylidene (=cyclopropylidenecyclopropane) syn‐1, a single diastereoisomer (Schemes 5 and 6). The structure of syn‐1 was undoubtedly elucidated by X‐ray single crystal diffraction. The coupling mechanism of the carbenoid cyclopropane is discussed (Scheme 7).
立体异构纯的内-和外--7-卤代-7-(三甲基锡烷基)苯并降冰片烯3-(=内-和外-(1-卤代-1a,2,7,7a-四氢-1H-环丙烷[ b ]锂锡或镁锡的金属转移选择性地获得了萘-1-基)三甲基锡(4)和6(方案2和3)。这些化合物与噻吩-2-羧酸铜(I)的反应在两种情况下均产生相应的C S-对称双环亚丙基(= cyclopropylidenecyclopropane)syn- 1,单个非对映体(方案5和6)。X射线单晶衍射无疑阐明了syn - 1的结构。讨论了类胡萝卜素环丙烷的偶联机理(方案7)。