α-L-diarylprolinol as the organocatalyst and K2CO3 as the additive has been accomplished. The spirocyclopropanes were isolated in high yield and up to 85 % ee. Notably, the asymmetric one-pot sequential approach to spirocyclopropanes proved to be a feasible process.
Highly diastereoselective spiro-cyclopropanation of 2-arylidene-1,3-indanediones and dimethylsulfonium ylides
作者:Jie Huang、Shaofa Sun、Ping Ma、Jian Wang、Kevin Lee、Yalan Xing、Yang Wu、Gangqiang Wang
DOI:10.1039/d1nj02886c
日期:——
This efficient and simple protocol features simple operations, mild conditions and excellent functional group compatibility. A variety of structurally interesting spiro-cyclopropanes were prepared in excellent yields and diastereomeric ratios (up to 97% yield and 20 : 1 dr). Also, ring expansion of the cyclopropanation product to quickly deliver a complex indeno[1,2-c]pyridazine structure showcased
2-亚芳基-1,3-茚二酮和二甲基锍叶立德的高度非对映选择性螺环丙烷化反应已通过碱诱导环化开发。这种高效简单的方案具有操作简单、条件温和、功能组兼容性好等特点。以优异的产率和非对映体比率(高达 97% 的产率和 20:1 dr)制备了各种结构有趣的螺环丙烷。此外,环丙烷化产物的扩环以快速提供复杂的茚并[1,2- c ]哒嗪结构展示了该方法的有趣应用。
An efficient organocatalytic enantioselective synthesis of spironitrocyclopropanes
作者:Utpal Das、Yi-Ling Tsai、Wenwei Lin
DOI:10.1039/c2ob26943k
日期:——
An organocatalytic asymmetric synthesis of spironitrocyclopropanes has been demonstrated starting from 2-arylidene-1,3-indandiones and bromonitroalkanes catalyzed by a cinchona-derived bifunctional organocatalyst. The products were obtained with excellent enantioselectivities, diastereoselectivities and with good yields.
An efficient organocatalytic quadruple cascadereaction resulting in spiroxindole scaffolds bearing five quaternary stereocenters is reported. The complex cascadereaction is triggered by the scarcely explored vinylogous Michael addition of 3-alkylidene oxindoles to fullysubstituted enones and demonstrates the usefulness of the latter as efficient Michael acceptors in generating complex caged products
Renewable RGO@CuI Nanocomposites for Redox Triggered Single Electron Transfer (SET) Reaction Under Aerobic and Anaerobic Conditions
作者:Upasana Gulati、U. Chinna Rajesh、Diwan S. Rawat
DOI:10.1002/cctc.202000314
日期:2020.7.21
and anaerobic single electron transfer (SET) reactions, respectively. The nanocatalysis study delineates two distinct mechanistic pathways for aerobic and anaerobic SET reactions. The present method offers the advantages of utilizing a renewable copper precursor for catalyst preparation, catalyst recyclability over five times, excellent product yields and green reactionconditions with minimum waste