The Regiochemistry of Carbenoid Insertion into Zirconacycles
作者:George J. Gordon、Tim Luker、Mark W. Tuckett、Richard J. Whitby
DOI:10.1016/s0040-4020(99)01094-7
日期:2000.4
lithium chloroallylides (allyl carbenoids) into a wide variety of unsymmetrical zirconacycles has been determined. In all but one case a single regioisomer was obtained. A combination of steric and electronic effects is needed to explain the results and imply that the carbenoid is acting predominantly as an electrophilic species. The first carbenoid insertion into a zirconacyclopentadiene is noted.
Alkylidene Carbene from Silyl Vinyl Iodide Provides Mechanistic Insights on Trimethylenemethane Diyl-Mediated Tandem Cyclizations
作者:Dong Whan Jee、Jinnie Myung、R. Daniel Little、Sunkyu Han、Hee-Yoon Lee
DOI:10.1021/acs.orglett.2c01622
日期:2022.6.24
We describe a method to generate alkylidenecarbenes via tetramethylammonium-fluoride-induced desilylation of silyl vinyl iodides. The reversible carbenegenerationfrom an iodovinyl anion enabled us to unearth mechanistic aspects of the trimethylenemethane (TMM) diyl cyclization reaction that could not be explored via previous methods. We observed that a slow diyl–diylophile cycloaddition can induce