Discovery of Stabilized Bisiodonium Salts as Intermediates in the Carbon-Carbon Bond Formation of Alkynes
作者:Toshifumi Dohi、Daishi Kato、Ryo Hyodo、Daisuke Yamashita、Motoo Shiro、Yasuyuki Kita
DOI:10.1002/anie.201007640
日期:2011.4.11
Ways and means to spirocycles: Pseudocyclic bisiodonium salts 1 stabilized by a secondary bonding interaction—an IIII⋅⋅⋅O⋅⋅⋅IIII pseudobridge linkage (circle) —were prepared by CC bond formation between aryl alkynes and a μ‐oxo‐bridged hypervalent iodine compound. The synthetic utility of salts 1 was demonstrated by their facile conversion into functionalized spirocycles by treatment with a nucleophile
方式和方法,以螺环:Pseudocyclic bisiodonium盐1由次级键合相互作用,一个I稳定化的III ⋅⋅⋅O⋅⋅⋅I III pseudobridge联动装置(圆)-were制备被C 芳炔和μ-之间C键形成含氧桥的高价碘化合物。盐1的合成效用通过用亲核试剂处理而容易地转化为官能化的螺环而得到证明。
Electrochemical Synthesis of Spiro[4.5]trienones through Radical‐Initiated Dearomative Spirocyclization
A novel and green route has been developed for the electrochemical synthesis of spiro[4.5]trienones through radical-initiated dearomative spirocyclization of alkynes with diselenides. This metal-free and oxidant-free electrosynthesis reaction was performed in an undivided cell under mild conditions. A variety of selenation spiro[4.5]trienones products were prepared in moderate-to-good yields, showing
spiro[4.5]trienones via alkylation/ipso-cyclization of activated alkynes with 4-alkyl-DHPs under transition-metal-free conditions is proposed. This alkylation successively undergoes the generation of alkyl radicals, addition of alkyl radicals to the alkynes, and intramolecular ipso-cyclization. The mechanism studies suggest that the alkylation/ipso-cyclization involves a radical process. This ipso-cyclization