Cp<sub>2</sub>TiCl<sub>2</sub>-Catalyzed Regioselective Hydrocarboxylation of Alkenes with CO<sub>2</sub>
作者:Peng Shao、Sheng Wang、Chao Chen、Chanjuan Xi
DOI:10.1021/acs.orglett.6b00665
日期:2016.5.6
Cp2TiCl2-catalyzed regioselective hydrocarboxylation of alkenes with CO2 to give carboxylic acids in high yields has been developed in the presence of iPrMgCl. The reaction proceeds with a wide range of alkenes under mild conditions. Styrene and its derivatives can transform to α-aryl carboxylic acids, and aliphatic alkenes can transform to form alkanoic acids.
The generation and use of a masked α-acyl cation in aromatic substitution reactions; Ag<sup>+</sup>induced reactions of 3-(bromomethyl)-5,6-dihydro-1,4,2-dioxazine derivatives
作者:Shimon Shatzmiller、Sorin Bercovici
DOI:10.1039/c39900000327
日期:——
The Ag+ inducedaromaticsubstitutionreactions of 3-(1-bromomethyl)-5,6-dihydro-1,4,2-dioxazinederivatives via an α-acylcation equivalent are described.
The present invention relates to the use of compounds of the formula (I), with radicals defined in the description, as antioxidants, to corresponding novel compounds and compositions, and to corresponding processes for the preparation of compounds and compositions.
The present invention relates to the use of compounds which do not themselves exhibit significant UV absorption in the UV-A or UV-B region, but are reactive under use conditions, for the development of UV-A or UV-B protection during use, to corresponding novel compounds and compositions, and to corresponding processes for the preparation of compounds and compositions.
Iron-Catalyzed, Highly Regioselective Synthesis of α-Aryl Carboxylic Acids from Styrene Derivatives and CO<sub>2</sub>
作者:Mark D. Greenhalgh、Stephen P. Thomas
DOI:10.1021/ja3045053
日期:2012.7.25
The iron-catalyzed hydrocarboxylation of aryl alkenes has been developed using a highly active bench-stable iron(II) precatalyst to give alpha-aryl carboxylic acids in excellent yields and with near-perfect regioselectivity. Using just 1 mol % FeCl2, bis(imino)pyridine 6 (1 mol %), CO2 (atmospheric pressure), and a hydride source (EtMgBr, 1.2 equiv), a range of sterically and electronically differentiated aryl alkenes were transformed to the corresponding alpha-aryl carboxylic acids (up to 96% isolated yield). The catalyst was found to be equally active with a loading of 0.1 mol %. Preliminary mechanistic investigations show that an iron-catalyzed hydrometalation is followed by transmetalation and reaction with the electrophile (CO2).