Formation of Hypervalent Complexes of PhCCSiF3 with Pyridine through Intermolecular Silicon···Nitrogen Interaction
摘要:
We report here the synthesis of trifluoro-phenylethynyl-silane (1) that forms with pyridine (Py), through intermolecular Si...N interaction, the pentacoordinate 1.Py complex and at low temperatures also the hexacoordinate 1.Py2 complex. 1H, 19F, 29Si, and 15N NMR spectra, as well as the first report for an intermolecular 29Si...15N one-bond spin-spin coupling, are presented for the two complexes. Quantum mechanical ab initio calculations (MP2/6-31G*) suggest a distorted trigonal bipyramid structure for the 1.Py complex and a nearly ideal octahedral structure for the 1.Py2 complex. The hypervalent complexes of 1 with Py described here imply a possible application of such Si...N intermolecular interactions in supramolecular chemistry.
Access to <i>Z</i>-Selective 1,3-Enynes via Ni-Catalyzed Intermolecular Cross-Alkylalkynylation of Terminal Alkynes
作者:Nan Xiao、Yi-Zhou Zhan、Huan Meng、Wei Shu
DOI:10.1021/acs.orglett.1c01728
日期:2021.7.2
facile synthesis of stereodefined 1,3-conjugated enynes via Ni-catalyzed intermolecular cross-alkylalkynylation of alkynes with unsaturated carbonyl compounds and alkynes or alkynyl silicates. The operational simple protocol proceeds at room temperature and tolerates a wide range of functional groups, providing an attractive alternative to carbonyl-tethered trisubstituted conjugated 1,3-enynes from easily
获得具有明确立体选择性的 1,3-共轭烯炔是非常理想和具有挑战性的。在此,我们报告了通过 Ni 催化的炔烃与不饱和羰基化合物和炔烃或炔基硅酸盐的分子间交叉烷基炔基化,轻松合成立体定义的 1,3-共轭烯炔。操作简单的协议在室温下进行,并且可以容忍广泛的官能团,为来自易于获得的起始材料的羰基束缚的三取代共轭 1,3-烯炔提供了一种有吸引力的替代方案。
Enantioselective alkynylation of carbonyl compounds with trimethoxysilylalkynes catalyzed by lithium binaphtholate
Enantioselective alkynylation of aldehydes and ketones was accomplished using trimethoxysilylalkynes as alkynylating reagents and lithium 3,3′-diphenylbinaphtholate as a catalyst. Optically active propargylic alcohols were obtained in good to high chemical yields and enantioselectivities. Alkynylation of acetylpyridines afforded biologically active pyridyl propargylic alcohols in good enantioselectivities
Enantioselective Trifluoromethylalkynylation of Alkenes via Copper-Catalyzed Radical Relay
作者:Liang Fu、Song Zhou、Xiaolong Wan、Pinhong Chen、Guosheng Liu
DOI:10.1021/jacs.8b07436
日期:2018.9.5
A novel enantioselective copper-catalyzed trifluoromethylalkynylation of styrenes, proceeding through a radical relay process, is described herein, which affords structurally diverse CF3-containing propargylic compounds in good yield with excellent enantioselectivities under very mild conditions. In addition, the reaction features wide substrate scope and good functional group tolerance. Moreover,
Enantioselective Intermolecular Aminoalkynylation of Styrenes via Copper-Catalyzed Radical Relay
作者:Zhoumi Hu、Liang Fu、Pinhong Chen、Weiguo Cao、Guosheng Liu
DOI:10.1021/acs.orglett.0c03826
日期:2021.1.1
alkenes through a radical relay process has been developed in this work, in which N-fluoro-N-alkylsulfonamides (NFASs) are used as nitrogen-centered radical precursors and alkynyltrimethoxysilanes as alkynylating reagents. This method presents an efficient and straightforward approach to various enantioenriched 2-alkynyl-2-arylethylamines in good yields with excellent enantioselectivity, and these products
Enantioselective Copper-Catalyzed Alkynylation of Benzylic C–H Bonds via Radical Relay
作者:Liang Fu、Zhihan Zhang、Pinhong Chen、Zhenyang Lin、Guosheng Liu
DOI:10.1021/jacs.0c05373
日期:2020.7.15
The first enantioselective alkynylation of benzylic C-H bonds via copper-catalyzed radical relay has been established herein, which provides an easy access to structurally diverse benzylic alkynes in good yields with excellent enantioselectivities. A key step for the asymmetriccopper-catalyzed radical relay process is the enantioselective capture of a benzylic radical with chiral (Box)CuII-alkynyl