Rh(III)-Catalyzed Regio- and Chemoselective [4 + 1]-Annulation of Azoxy Compounds with Diazoesters for the Synthesis of 2<i>H</i>-Indazoles: Roles of the Azoxy Oxygen Atom
作者:Zhen Long、Zhigang Wang、Danni Zhou、Danyang Wan、Jingsong You
DOI:10.1021/acs.orglett.7b00631
日期:2017.6.2
tandem C–H alkylation/intramolecular decarboxylative cyclization of azoxy compounds with diazoesters for the synthesis of 3-acyl-2H-indazoles is disclosed. The azoxy instead of the azo group enables a distinct approach for cyclative capture, leading to a [4 + 1]-annulation rather than a classic [4 + 2] manner. The azoxy oxygen atom is traceless after annulation, and further removal from the product is
Convergent Synthesis of Dihydropyrans from Catalytic Three-Component Reactions of Vinylcyclopropanes, Diazoesters, and Diphenyl Sulfoxide
作者:Ya-Lin Zhang、Rui-Ting Guo、Heng Luo、Xin-Shen Liang、Xiao-Chen Wang
DOI:10.1021/acs.orglett.0c01992
日期:2020.7.17
three-component reaction of vinylcyclopropanes, diazoesters, and diphenyl sulfoxide has been developed. The reaction gives polysubstituted dihydropyrans as the reactionproducts. Mechanistic studies indicate that isomerization of vinylcyclopropanes gives conjugated dienes, which then undergo [4 + 2]-cycloaddition with vicinaltricarbonyl compounds generated by oxygen atom transfer from diphenyl sulfoxide
Rhodium-Catalyzed C−H Functionalization of Indoles with Diazo Compounds: Synthesis of Structurally Diverse 2,3-Fused Indoles
作者:Mengying Gao、Yaxi Yang、Hua Chen、Bing Zhou
DOI:10.1002/adsc.201700974
日期:2018.1.4
functionalization of indoles with diazocompounds, followed by intramolecular nucleophilic addition to C=O or C=C bonds, is reported for divergent synthesis of 2,3‐fused indoles. Besides acceptor/acceptor diazocompounds, donor/acceptor diazocompounds are broadly tolerated, giving various 2,3‐fused indoles with perfect diastereocontrol. Notably, a selective C−H dialkylation reaction at C2 and C7 position of
A novel Zn(OAc)2-catalyzed three-component tandem cyclization reaction of isocyanides, α-diazoketones and anhydrides has been developed. The reaction demonstrates the wide scope of substrates and provides a novel and efficient strategy for the synthesis of polysubstituted maleimides from readily available substrates in a single step.
A Catalytic Homo-Nazarov Cyclization Protocol for the Synthesis of Heteroaromatic Ring-Fused Cyclohexanones
作者:Lien H. Phun、Dadasaheb V. Patil、Marchello A. Cavitt、Stefan France
DOI:10.1021/ol200305n
日期:2011.4.15
A general protocol for the catalytichomo-Nazarovcyclization of cyclopropyl heteroaryl ketones has been developed, which employs indium triflate as the promoter. A range of heteroaromaticring-fused cyclohexanones was synthesized in 56−91% yield using this protocol. An example of a tandem cyclopropanation/homo-Nazarovcyclization is also reported in which the one-pot yield is greater than the overall