开发了两种方法将异恶唑-5-酮转化为2,3-二氢-6 H -1,3-恶嗪-6-酮。第一个涉及芳基重氮乙酸酯的铑催化反应,导致铑卡宾中间体插入异恶唑-5-酮的N–O键中。第二种方法涉及将芳基重氮乙酸酯转化为相应的甲苯磺酸酯,然后在无金属的一锅法中与异恶唑-5-酮反应。这些研究说明了无需金属催化剂即可实现卡宾样转化的另一种方法。
Rhodium-catalyzed enantioselective cyclopropanation of electron-deficient alkenes
作者:Hengbin Wang、David M. Guptill、Adrian Varela-Alvarez、Djamaladdin G. Musaev、Huw M. L. Davies
DOI:10.1039/c3sc50425e
日期:——
The rhodium-catalyzed reaction of electron-deficient alkenes with substituted aryldiazoacetates and vinyldiazoacetates results in highly stereoselective cyclopropanations. With adamantylglycine derived catalyst Rh2(S-TCPTAD)4, high asymmetric induction (up to 98% ee) can be obtained with a range of substrates. Computational studies suggest that the reaction is facilitated by weak interaction between
Asymmetric Three-Component Reaction for the Synthesis of Tetrasubstituted Allenoates via Allenoate-Copper Intermediates
作者:Yu Tang、Jian Xu、Jian Yang、Lili Lin、Xiaoming Feng、Xiaohua Liu
DOI:10.1016/j.chempr.2018.04.012
日期:2018.7
three-component reaction of α-diazoesters with terminal alkynes and isatins was achieved. This one-pot synthesis gave rise to axially chiral tetrasubstituted allenoates bearing a stereogenic center. The chiral guanidinium salt/CuBr/YBr3 catalytic system proved efficient and highly diastereo- and enantioselective for a wide range of alkynes, aromatic α-diazoesters, and isatins under mild reaction conditions
Three-Component Synthesis of Isoquinoline Derivatives by a Relay Catalysis with a Single Rhodium(III) Catalyst
作者:Chao Zhou、Jijun Jiang、Jun Wang
DOI:10.1021/acs.orglett.9b01456
日期:2019.7.5
A rhodium(III)-catalyzed one-pot three-component reaction of N-methoxybenzamide, α-diazoester, and alkyne was developed, providing an alternative way to synthesize isoquinoline derivatives. Mechanistically, it is a relay catalysis, and the reaction occurred via successive O-alkylation and C–H activation processes, both of which were promoted by the same catalyst.
Copper-Catalyzed Reaction of α-Aryldiazoesters with Terminal Alkynes: A Formal [3 + 2] Cycloaddition Route Leading to Indene Derivatives
作者:Eun Ju Park、Seok Hwan Kim、Sukbok Chang
DOI:10.1021/ja808080h
日期:2008.12.24
It was discovered that Cu(IPr)Cl-catalyzed reaction of terminal alkynes with alpha-aryldiazoacetates provides indene derivatives, formal [3 + 2] cycloaddition adducts. Excellent regio- and chemoselectivity were observed to afford either 3H- or 1H-indene esters depending on the reaction conditions employed. The reaction is proposed to proceed via tandem processes: alkyne insertion into copper-carbenoid
Michael-initiated ring closure of aryldiazoacetates and α-substituted acroleins under acid catalysis offers a unique opportunity for the stereoselective formation of various tetrasubstituted cyclopropanes.