Novel (3 + 2) photocycloadditions with 3-(1-alkynyl)cyclohexenones and tetramethylethylene
作者:Paul Margaretha、H. J. Rathjen、Steven Wolff、William C. Agosta
DOI:10.1039/c39880000841
日期:——
Irradiation of 3-alkynylcyclohexenones (3) with tetramethylethylene gives rise to novel (3 + 2) cycloadducts that can be explained mechanistically in terms of closure of an initial biradical (6) to a vinyl carbene (7), followed by stabilization of the carbene.
Palladium-Catalyzed Decarboxylative Coupling of Alkynyl Carboxylic Acids and Alkenyl Tosylates for the Synthesis of Enynones
作者:Subeen Yu、Eunjeong Cho、Jimin Kim、Sunwoo Lee
DOI:10.1021/acs.joc.7b02175
日期:2017.10.20
A palladium-catalyzed decarboxylativecoupling reaction was developed for the synthesis of 3-(1-alkynyl)-2-cyclohexen-1-ones. A variety of alkynyl carboxylic acids were coupled with 3-oxocyclohexenyl tosylates to afford the corresponding enynones in good to excellent yields. The developed catalytic system is phosphine free and showed good tolerance toward various functionalities such as chloride, cyano
Novel [3+2] photocycloadditions of 3-(1-alkynyl)-2-cycloalken-1-ones with alkenes
作者:H. J. Rathjen、Paul Margaretha、Steven Wolff、William C. Agosta
DOI:10.1021/ja00010a035
日期:1991.5
Photochemical cycloaddition of 3-alkynylcycloalkenones with tetramethylethylene at ∼40 o C leads to mixtures of 1:1 adducts that arise largely from 1,5 closure of the biradical intermediate (eq 1), providing examples of a novel [3+2] cycloaddition reaction. Similar reactions occur between these same ketones and 1,1-dimethoxy-2-methylpropene and 1,1-dimethoxyethylene. This and previously observed temperature
3-炔基环烯酮与四甲基乙烯在约 40 o C 的光化学环加成产生 1:1 加合物的混合物,这些加合物主要来自双自由基中间体的 1,5 闭合(方程式 1),提供了新型 [3+2] 环加成反应的例子. 类似的反应发生在这些相同的酮和 1,1-二甲氧基-2-甲基丙烯和 1,1-二甲氧基乙烯之间。这种和之前观察到的温度对三线态双自由基相关重排的影响表明,这种双自由基重排发生在系统间交叉到单线态之前并与之竞争