Rhenium‐Catalyzed Decarboxylative Tri‐/Difluoromethylation of Styrenes with Fluorinated Carboxylic Acid‐Derived Hypervalent Iodine Reagents
作者:Yin Wang、Yunhui Yang、Congyang Wang
DOI:10.1002/cjoc.201900296
日期:2019.12
Herein, unprecedented rhenium‐catalyzed decarboxylative oxytri‐/difluoromethylation and Heck‐type trifluoromethylation of styrenes have been developed by using hypervalent iodine(III) reagents derived from cheap, stable, and easy‐handling fluorinated carboxylic acids. Mechanistic studies revealed a radical decarboxylative trifluoromethylation pathway occurring in these reactions.
and regioselective vicinal dioxidation of alkenes under transition metal and organic peroxide free conditions has been developed. This approach uses N-hydroxyphthalimide and its analogues as the transient nitroxyl-radical precursors and 2,2,6,6-tetramethylpiperidine-1-oxoammonium tetrafluoroborate (TEMPO+BF4–) as the oxidant as well as the source of persistent nitroxide. By employing this method, multifarious
strategy to turnover H‐MII‐X complexes has enabled both intra‐ and intermolecular Mizoroki–Heck (MH)‐type reactions of arylcyanides that are challenging to realize under traditional, basic conditions. Initially, a cascade carbonickelation/MH reaction of 2‐cyanostyrenes was achieved using a key alkyne transfer hydrocyanation step. Mechanistic experiments supported the proposed catalytic cycle, including
一种新的转移H-M II - X配合物的转移加氢官能化策略,使芳基氰化物的分子内和分子间Mizoroki-Heck(MH)型反应成为可能,这在传统的基本条件下很难实现。最初,使用关键的炔烃转移氢氰化步骤实现了2-氰基苯乙烯的级联羰基化/ MH反应。机械实验支持了拟议的催化循环,包括促成转移的转移氢氰化步骤。然后将反应性扩展至苄腈和苯乙烯的分子间MH反应。
A Ligand-Directed Catalytic Regioselective Hydrocarboxylation of Aryl Olefins with Pd and Formic Acid
作者:Wei Liu、Wenlong Ren、Jingfu Li、Yuan Shi、Wenju Chang、Yian Shi
DOI:10.1021/acs.orglett.7b00507
日期:2017.4.7
An effective Pd-catalyzed hydrocarboxylation of aryl olefins with Ac2O and formic acid is described. A variety of 2- and 3-arylpropanoic acids can be regioselectively formed by the judicious choice of ligand without the use of toxic CO gas.
Low pressure vinylation of aryl and vinyl halides via Heck–Mizoroki reactions using ethylene
作者:Craig R. Smith、T.V. RajanBabu
DOI:10.1016/j.tet.2009.11.017
日期:2010.1
and 2 equiv of potassium acetate react with ethylene under ambient pressure (15–30 psi) to give the corresponding vinylarenes. The reactions work with both electron-deficient and electron-rich aryl compounds and tolerate wide variety of common functional groups. Vinyl bromides lead to 1,3-dienes in moderate yields.