Tandem michael-michael-ring closure (mimirc) reactions
作者:Gary H. Posner、John P. Mallamo、Alison Y. Black
DOI:10.1016/s0040-4020(01)93265-x
日期:——
A new sequence of reactions involving tandem Michael-Michael-ring closure (MIMIRC) has been developed for efficient formation of three C-C bonds in one reaction vessel. The terminal ring closure reaction proceeds via either a 1,3- or a 1,6-cyclization, and this methodology also serves for construction of quaternary C centers. The usefulness of MIMIRC reactions is demonstrated by efficient assembly
Visible-light-promoted oxidative halogenation of alkynes
作者:Yiming Li、Tao Mou、Lingling Lu、Xuefeng Jiang
DOI:10.1039/c9cc07655g
日期:——
In nature, halogenation promotes the biological activity of secondary metabolites, especially geminal dihalogenation. Related natural molecules have been studied for decades. In recent years, their diversified vital activities have been explored for treating various diseases, which call for efficient and divergent synthetic strategies to facilitate drug discovery. Here we report a catalyst-free oxidative
K<sub>2</sub>S<sub>2</sub>O<sub>8</sub>-Mediated Difunctionalization of C≡C Bonds in Water: A Simple and Efficient Approach to <font>α</font>,<font>α</font>-Dihaloacetophenones from Phenylacetylenes and NaX
作者:Jing-Yu Wang、Qing Jiang、Can-Cheng Guo
DOI:10.1080/00397911.2014.928938
日期:2014.11.2
Abstract A novel K2S2O8-mediated oxy-1,1-dihalogenation of alkynes with NaX in the presence of water has been developed, affording α,α-dihaloacetophenones in moderate to good yields. The advantages of this reaction are mild reaction conditions, operational simplicity, and use of pure water as reaction medium. A plausible reaction mechanism is proposed on the basis of mechanistic studies. GRAPHICAL
Halocarbocyclization versus dihalogenation: substituent directed iodine(<scp>iii</scp>) catalyzed halogenations
作者:Maciej Stodulski、Alissa Goetzinger、Stefanie V. Kohlhepp、Tanja Gulder
DOI:10.1039/c3cc49850f
日期:——
The nucleophilicity of the substituents in iodobenzene pre-catalysts have a huge impact on product selectivity in iodine(III) triggered halogenations, steering the reactivity from solely carbocyclizations towards dihalogenations. Utilizing this catalyst-dependent reactivity a diastereo- and chemoselective dihalogenation method was established allowing the conversion of structurally and electronically