Department of Chemistry, The University of Vermont , Burlington, Vermont 05405, United States.
Department of Chemistry and Biochemistry, University of California , Los Angeles, California 90095, United States.
J Org Chem. 2017 Apr 7;82(7):4001-4005. doi: 10.1021/acs.joc.7b00407. Epub 2017 Mar 27.
Cationic 1-aza-2-azoniaallene salts react with structurally constrained alkenes in intramolecular reactions by C-H insertion at the allylic position, or by (2+1)-cycloaddition with the alkene followed by ring opening. The latter reaction gives further evidence of the nitrenium-like character of 1-aza-2-azoniaallene salts. DFT calculations show that alkene addition is intrinsically more favorable, but that predistortion can lead to C-H insertion.
阳离子 1-氮杂-2-氮杂环丙烯盐与结构受约束的烯烃在分子内反应中,通过在烯丙位的 C-H 插入,或者通过与烯烃的 (2+1)-环加成,然后开环进行反应。后一种反应进一步证明了 1-氮杂-2-氮杂环丙烯盐的类氮正离子性质。DFT 计算表明,烯烃加成在本质上更有利,但预变形可以导致 C-H 插入。