Decarboxylative cyclizations and cycloadditions of palladium-polarized aza-ortho-xylylenes
摘要:
Vinyl benzoxazinones undergo decarboxylation in the presence of palladium catalysts to form palladium-polarized aza-ortho-xylylenes, which are versatile reaction intermediates. These palladium-polarized aza-ortho-xylylenes are generated under exceptionally mild conditions and undergo a plethora of different reactions depending on the reaction conditions. Specifically, they undergo dimerization reactions to produce macrocycles, cyclizations to form dihydroquinolines, cycloadditions with electrophilic p-bonds, and nucleophilic attack by amines. Thus, a wide array of structurally unique aniline derivatives can be accessed from these unique intermediates. (C) 2009 Elsevier Ltd. All rights reserved.
Access to 5,6-Spirocycles Bearing Three Contiguous Stereocenters via Pd-Catalyzed Stereoselective [4 + 2] Cycloaddition of Azadienes
作者:Siti Nur Fairuz Binte Sheikh Ismail、Binmiao Yang、Yu Zhao
DOI:10.1021/acs.orglett.1c00505
日期:2021.4.16
[4 + 2] cycloaddition of benzofuran-derived azadienes with vinyl benzoxazinanones, which represents a rare highly stereoselective cycloaddition of this class of fused azadienes as a two-atom synthon. The use of a phosphoramidite ligand bearing a chiral secondary amine with a simple biphenyl backbone proved to be the key to construct the novel spirocyclic tetrahydroquinoline scaffold containing three
Iridium and a Brønsted acid cooperatively catalyzed chemodivergent and stereoselective reactions of vinyl benzoxazinones with azlactones
作者:Meng Sun、Xiao Wan、Si-Jia Zhou、Guang-Jian Mei、Feng Shi
DOI:10.1039/c8cc08962k
日期:——
Under cooperativecatalysis of iridium and a Brønsted acid, different C4-substituted azlactones react with vinyl benzoxazinones via a formal [4+2] cycloaddition or substitution reaction in a chemo- and stereoselective mode. Furthermore, the catalyticasymmetric version of the formal [4+2] cycloaddition established cooperativecatalysis of iridium and a chiral thiourea-tertiary amine.
Palladium-catalyzed enantioselective linear allylic alkylation of vinyl benzoxazinanones: An inner-sphere mechanism
作者:Kai Wang、Binli Wang、Xianghui Liu、Hongjun Fan、Yan Liu、Can Li
DOI:10.1016/s1872-2067(20)63751-2
日期:2021.7
Palladium-catalyzed asymmetric allylic alkylation (AAA) of vinyl benzoxazinanones has become an important strategy for the synthesis of chiral nitrogen-containing heterocycle compounds. However, the asymmetric synthesis of linear-selective products has rarely been reported. The simultaneous control of regio-, E/Z- and enantioselectivities constitutes a major challenge and inhibits the advancement of
Asymmetric Cycloadditions of Palladium-Polarized Aza-<i>o</i>-xylylenes
作者:Chao Wang、Jon A. Tunge
DOI:10.1021/ja801742h
日期:2008.7.1
benzoxazinanones undergo highlyenantioselective decarboxylative cycloadditions with electron-deficient olefins in the presence of palladium catalysts. Palladium induces the decarboxylation of the parent benzoxazinanones under mild conditions to produce an intermediate that can be described as a polarized aza-o-xylylene. These intermediates undergo a formal [4 + 2] cycloaddition with good Michael acceptors
Palladium-Catalyzed Decarboxylative [4+2] Cycloaddition of Vinyl Benzoxazinanones with Cyclic N-Sulfimines: Stereoselective Synthesis of Benzosulfamidate-Fused Tetrahydroquinazolines
作者:Dasom Mun、Eunjin Kim、Sung-Gon Kim
DOI:10.1055/s-0037-1610685
日期:2019.6
Abstract Methods for the catalytic synthesis of highly functionalized benzosulfamidate-fused tetrahydroquinazolines are presented. The decarboxylative [4+2] cycloaddition of vinyl benzoxazinanones with benzoxathiazine 2,2-dioxides catalyzed by Pd(PPh3)4 affords fused-tetrahydroquinazolines with high diastereoselectivities. Alternatively, catalytic asymmetric [4+2] cycloaddition employing a chiral palladium-containing