Conversion of Cyclic Ketones to 2,3-Fused Pyrroles and Substituted Indoles
作者:Joshua S. Alford、Jillian E. Spangler、Huw M. L. Davies
DOI:10.1021/ja405043g
日期:2013.8.14
A highly effective synthesis of 2,3-fused pyrroles from cyclicketones has been achieved. The transformation includes a rhodium-catalyzed reaction of 4-alkenyl-1-sulfonyl-1,2,3-triazoles featuring an unusual 4π electrocyclization. The methodology was further extended to the synthesis of indoles using a one-pot reaction starting from 1-ethynylcyclohexenes.
Reactions of Vinylidenecyclopropanes with Diphenyl Diselenide in the Presence of AIBN and Thermally-Induced Further Transformations
作者:Wei Yuan、Yin Wei、Min Shi、Yuxue Li
DOI:10.1002/chem.201103461
日期:2012.1.27
vinylidenecyclopropanes with diphenyl diselenide in the presence of AIBN and upon heating gives the corresponding bicyclo[3.1.0]hexane derivatives in good yields. These compounds undergo thermal‐induced radical 1,4‐hydrogen shifts through a ring‐opening pathway of allylic cyclopropane to give the corresponding cyclohexene derivatives stereoselectively in good yields at 200 °C (see scheme).
Acid-Catalyzed Cascade Ring-Opening and Addition Reactions of Arylvinylcyclopropenes with α,β-Unsaturated Substrates, Scope and Limitations
作者:Zhi-Bin Zhu、Min Shi
DOI:10.1021/jo802786r
日期:2009.3.20
produce the Diels−Alder adducts in moderate to good yields through a cascade ring-opening reaction/Diels−Alder cycloaddition. On the other hand, strong Brønsted acid TfOH can promote the cascade intramolecular Friedel−Crafts/1,4-addition reaction to produce indene derivatives in moderate to good yields under mild conditions. The acidity of the catalysts plays a key role in these reactions.
Rapid access to <i>t</i>-butylalkylated olefins enabled by Ni-catalyzed intermolecular regio- and <i>trans</i>-selective cross-electrophile <i>t</i>-butylalkylation of alkynes
作者:Yi-Zhou Zhan、Huan Meng、Wei Shu
DOI:10.1039/d2sc00487a
日期:——
distinct alkyl bromides to afford olefins with two aliphatic substituents. The reductive conditions circumvent the use of organometallic reagents, enabling the cross-dialkylation process to occur at room temperature from two different alkyl bromides. This operationally simple protocol provides a straightforward and practical access to a wide range of stereodefined dialkylated olefins with broad functional
在炔烃的碳双官能化中,炔烃的立体选择性二烷基化是最具挑战性的转化,因为相关的竞争性副反应,因此仍然不发达。在此,我们报道了第一次 Ni 催化的炔烃与两种不同的烷基溴化物的区域选择性和反式选择性交叉二烷基化反应,得到具有两个脂肪族取代基的烯烃。还原条件避免了有机金属试剂的使用,使交叉二烷基化过程能够在室温下由两种不同的烷基溴进行。这种操作简单的协议提供了一种直接且实用的途径,可以从容易获得的起始材料中获得具有广泛官能团耐受性的各种立体定义的二烷基化烯烃。
Asymmetric Oxidative Lactonization of Enynyl Boronates
We present herein the first oxidation of enynylboronates for the synthesis of γ-lactones, including spiro-, and fused-butanolides as well as butenolides that are prevalent in nature products and bioactive molecules. The asymmetric version of this oxidation was also achieved in the presence of chiral ketone and Oxone. This process successively involves the oxidation of C(sp)−B bond, the epoxidation