A highly efficient N,N′‐dioxide–NiII catalyst system for the catalytic [3+2] cycloaddition of indoles with epoxides through CC cleavage of oxiranes was accomplished under mild conditions. It provided a promising approach for chiral furo[3,4‐b]indoles in up to 98 % yield with up to 91 % enantiomeric excess (ee) and >95:5 diastereomeric ratio (d.r.).
一个高效Ñ,Ñ '二氧化物-镍II为吲哚与环氧化物至C催化的[3 + 2]环加成催化剂体系环氧乙烷的C ^裂解温和的条件下完成的。它为手性呋喃[3,4- b ]吲哚提供了一种有前途的方法,产率高达98%,对映体过量(ee)高达91%,非对映体比率(dr)大于95:5。
Synthesis of 3-Oxazolines via SnCl4-Promoted Formal [3+2] Cycloaddition of Donor–Acceptor Oxiranes and Nitriles
作者:Xiaofei Zeng、Guofu Zhong、Hai Zhou、Yan Xie
DOI:10.1055/s-0034-1380216
日期:——
A novel SnCl4-promoted formal [3+2] cycloaddition of donor–acceptor oxiranes and nitrilesvia chemoselective C–C bond breakage was developed. This reaction provides an efficient and practical method for the preparation of 3-oxazolines in good yields (up to 89%).
Ni(ClO4)2-catalysed regio- and diastereoselective [3+2] cycloaddition of indoles and aryl oxiranyl-dicarboxylates/diketones: a facile access to furo[3,4-b]indoles
Ni(ClO(4))(2).6H(2)O-catalysed regioselective and diastereoselective [3+2]-annulations of aryl oxiranyl-dicarboxylates and indoles via selective C-C bond cleavage of oxirane were revealed. The cycloadditions proceed smoothly with high regio- and diastereoselectivity under mild conditions leading to 1H-furo[3,4-b]indoles in good to excellent yields.
Reaction of Two Differently Functionalized Oxiranes with Nickel Perchlorate: A Modular Entry to Highly Substituted 1,3-Dioxolanes
作者:Zuliang Chen、Yuanjing Xiao、Junliang Zhang
DOI:10.1002/ejoc.201300558
日期:2013.8
Nickelperchlorate catalyzed sequential Meinwald rearrangement of a terminal oxirane through C–O bond cleavage, and cycloaddition with a donor–acceptor oxirane through C–C bond cleavage was developed. The same catalyst mediates the ring opening of the oxirane moiety in twodifferent ways. This method provides an alternative route to synthesize highlysubstituted1,3-dioxolanes by using oxiranes instead
Divergence of Carbonyl Ylide Reactions as a Function of Diazocarbonyl Compound and Aldehyde Substituent: Dioxolanes, Dioxolenes, and Epoxides
作者:Albert E. Russell、Jonathan Brekan、Luisa Gronenberg、Michael P. Doyle
DOI:10.1021/jo049403y
日期:2004.8.1
The products from dirhodium(II) acetate-catalyzed reactions between diazocarbonyl compounds and a series of benzaldehydes demonstrate the extent of competition between intramolecular and intermolecular trapping of carbonylylide intermediates and the electronic effects that govern these transformations. With dimethyl diazomalonate, competition exists between dioxolane and epoxide formation so that