Trifluoromethylation of Unactivated Alkenes with Me<sub>3</sub>SiCF<sub>3</sub> and <i>N</i>-Iodosuccinimide
作者:Xinkan Yang、Gavin Chit Tsui
DOI:10.1021/acs.orglett.9b00332
日期:2019.3.1
A novel approach to the trifluoromethylation of unactivated alkenes is presented. This reaction is promoted by N-iodosuccinimide (NIS) undervisiblelight irradiation without the need for photocatalysts. The mild conditions allow the direct synthesis of useful trifluoromethylated (E)-alkenes from readily available alkene feedstocks with excellent functional group tolerability. In addition, using easy-to-handle
We identified 2-phenylisophosphindoline 2-oxide as a suitable and potentially tunable catalyst for the catalytic Wittigreaction of aldehydes with activated organohalides. This catalyst was obtained by a straightforward two-step synthesis. Trimethoxysilane proved to be an efficient reducing agent for the in situ generation and regeneration of the catalyst from the corresponding phosphane oxide. Sodium
Cu(I) Tol-BINAP-Catalyzed Enantioselective Michael Reactions of Grignard Reagents and Unsaturated Esters
作者:Shun-Yi Wang、Shun-Jun Ji、Teck-Peng Loh
DOI:10.1021/ja0666046
日期:2007.1.1
A highly efficient regio- and enantioselective catalytic asymmetric addition of Grignard regeants to α,β-unsaturated esters promoted by the CuI-Tol-BINAP system is described.
First Microwave-Assisted Catalytic Wittig Reaction
作者:Thomas Werner、Marcel Hoffmann、Sunetra Deshmukh
DOI:10.1002/ejoc.201403113
日期:2014.11
introduce a novel catalyticWittigreaction based on an inexpensive and readily available phosphane oxide as a precatalyst. The performance of the reaction under microwave irradiation led to significantly improved yields and reaction rates relative to those obtained under conventional heating. Moreover, herein we enclose the first example of the asymmetric catalyticWittigreaction based on a chiral
Scope and Limitation of the Microwave-Assisted Catalytic Wittig Reaction
作者:Marcel Hoffmann、Sunetra Deshmukh、Thomas Werner
DOI:10.1002/ejoc.201500310
日期:2015.7
We have developed a microwave-assisted catalyticWittigreaction. In this paper, we give full account of the scope and limitations of this reaction. A screening of various commercially available phosphine oxides as precatalysts revealed Bu3P=O to be the most promising candidate. We tested 10 silanes for the in situ reduction of the phosphine oxide to generate Bu3P as the actual catalyst. Different
我们开发了一种微波辅助催化 Wittig 反应。在本文中,我们充分考虑了该反应的范围和局限性。对各种市售氧化膦作为预催化剂的筛选表明,Bu3P=O 是最有希望的候选者。我们测试了 10 种硅烷原位还原氧化膦以生成 Bu3P 作为实际催化剂。测试不同的环氧化物作为掩蔽碱。在这方面,环己烯氧化物和丁烯氧化物被证明是合适的。该反应可在 125 °C 下进行,但在 150 °C 下可获得更高的产率和 E/Z 选择性。在优化的反应条件下,报道了各种醛类转化为相应烯烃的40多个实例。以高达 88% 的产率获得了具有高 E 选择性的产物。