Rhodium(<scp>iii</scp>)-catalyzed C–H/C–C activation sequence: vinylcyclopropanes as versatile synthons in direct C–H allylation reactions
作者:Jia-Qiang Wu、Zhi-Ping Qiu、Shang-Shi Zhang、Jing-Gong Liu、Ye-Xing Lao、Lian-Quan Gu、Zhi-Shu Huang、Juan Li、Honggen Wang
DOI:10.1039/c4cc07839j
日期:——
Succession of C-Hactivation and C-Cactivation was achieved by using a single rhodium(III) catalyst. Vinylcyclopropanes were used as versatile coupling partners. Mechanistic studies suggest that the olefin insertion step is rate-determining and a facile beta-carbon elimination is involved, which represents a novel ring opening mode of vinylcyclopropanes.
Synergistic Catalysis: Enantioselective Ring Expansion of Vinyl Cyclopropanes Combining Four Catalytic Cycles for the Synthesis of Highly Substituted Spirocyclopentanes Bearing up to Four Stereocenters
作者:Marta Meazza、Ramon Rios
DOI:10.1002/chem.201601893
日期:2016.7.11
A double synergistic cascade reaction is reported, combining transition metal and amine catalysis. The reaction between vinyl cyclopropanes and enals renders the final cyclopentane derivatives in excellent yields and stereoselectivities.
This paper is dedicated to Professor Dieter Enders on the occasion of his70thbirthday. He has always been a source of inspiration to develop new cascade reactions. Abstract We present a formal [3+2] cycloaddition based on synergistic catalysis. Vinylcyclopropanes derived from cyanoesters react with enals by dual activation using palladium(0) and secondary amines to form the corresponding cyclopentanes
The stereoselective [3 + 2] cycloaddition between vinylcyclopropanes and α,β-unsaturatedaldehydes promoted by combined palladium and organocatalysis is disclosed. The unique synergistic catalytic system allows for the stereoselective formation of highly substituted cyclopentanes with up to four stereocenters in high yields and selectivities. Vinylcyclopropanes with two different geminal substituents
Rhodium(III)‐Catalyzed Direct C7 Allylation of Indolines via Sequential C−H and C−C Activation
作者:Qiuling Wang、Chang‐Lei Zhi、Pei‐Pei Lu、Shuang Liu、Xinju Zhu、Xin‐Qi Hao、Mao‐Ping Song
DOI:10.1002/adsc.201801496
日期:2019.3.15
A rhodium‐catalyzedC7 allylation of indolines with vinylcyclopropanes is reported via chelation‐assisted tandem C−H and C−C bond activation under mild conditions. A wide range of substrate proceeds smoothly to provide the allylated products in high yields with good functional group compatibility. Mechanistic studies reveal that the rhodacycle species is probably the key intermediate.