Acyclic nitronate olefin cycloaddition (ANOC): regio- and stereospecific synthesis of isoxazolines
作者:Liang Ma、Luyao Kou、Feng Jin、Xionglve Cheng、Suyan Tao、Gangzhong Jiang、Xiaoguang Bao、Xiaobing Wan
DOI:10.1039/d0sc05607c
日期:——
We report the first demonstrations of intra- and intermolecular acyclic nitronate olefin cycloaddition (ANOC) reactions that enable the highly efficient syntheses of isoxazolines bearing various functional groups. This general approach to accessing γ-lactone fused isoxazolines was hitherto unprecedented. The room temperature transformations reported herein exhibit wide substrate scopes, as evidenced
Silver-Catalyzed Cross-Olefination of Donor and Acceptor Diazo Compounds: Use of<i>N</i>-Nosylhydrazones as Diazo Surrogate
作者:Zhaohong Liu、Binbin Liu、Xue-Feng Zhao、Yan-Bo Wu、Xihe Bi
DOI:10.1002/ejoc.201601610
日期:2017.1.26
The cross-olefination reaction of donor and acceptor diazocompounds is reported. The use of N-nosylhydrazones as the diazo surrogates and the dependence on silver catalysis are crucial for the reaction development. A variety of (hetero)aryl N-nosylhydrazones and α-diazo esters, amides, and phosphonates were compatible, affording functionalized alkenes in good-to-high yields with moderate Z/E selectivity
[3 + 2] cycloaddition and subsequent oxidative dehydrogenation between alkenes and diazo compounds: a simple and direct approach to pyrazoles using TBAI/TBHP
作者:Ying Shao、Jingjing Tong、Yanwei Zhao、Hao Zheng、Liang Ma、Meihua Ma、Xiaobing Wan
DOI:10.1039/c6ob01522k
日期:——
sequential [3 + 2] cycloaddition and oxidative dehydrogenation reactions using TBHP as the primary oxidant. In comparison with previous cases toward pyrazoles from alkenes and diazocompounds, alkenes without a pre-organized leaving group were applied in this transformation. In addition, this methodology was distinguished by its broad substrate scope, commercially available inexpensive starting materials
Reusable and highly enantioselective water-soluble Ru(II)-<i>Amm</i>-Pheox catalyst for intramolecular cyclopropanation of diazo compounds
作者:Hamada S A Mandour、Yoko Nakagawa、Masaya Tone、Hayato Inoue、Nansalmaa Otog、Ikuhide Fujisawa、Soda Chanthamath、Seiji Iwasa
DOI:10.3762/bjoc.15.31
日期:——
highly enantioselective catalyst for the intramolecularcyclopropanation of various diazo ester and Weinreb amide derivatives was developed. The reactions catalyzed by a water-soluble Ru(II)-Amm-Pheox catalyst proceeded smoothly at room temperature, affording the corresponding bicyclic cyclopropane ring-fused lactones and lactams in high yields (up to 99%) with excellent enantioselectivities (up to
Interception of Radicals by Molecular Oxygen and Diazo Compounds: Direct Synthesis of Oxalate Esters Using Visible-Light Catalysis
作者:Meihua Ma、Weiwei Hao、Liang Ma、Yonggao Zheng、Pengcheng Lian、Xiaobing Wan
DOI:10.1021/acs.orglett.8b02487
日期:2018.9.21
The synthesis of oxalateesters through a radical process, rather than the traditional ionic reaction, has been well developed in which the radicals induced by visible light are trapped by molecular oxygen and diazo compounds under room temperature. This reaction is operationally simple, mild, and shows broad substrate scopes in α-bromo ketones and diazo compounds.