C (sp3) -H 键的直接和可控氧化的发展非常重要。在此,公开了在无金属反应条件下碘催化的(芳基)(杂芳基)甲烷到(芳基)(杂芳基)甲醇的可控氧化。在二甲亚砜存在下,由碘/甲硅烷基氯和 HI 作为添加剂组成的催化体系选择性地氧化 C (sp3) -H 键,而不会过度氧化成相应的酮。以良好的收率获得了治疗上重要的芳基杂芳基甲醇衍生物。初步机理研究证明氧气的主要来源是DMSO。
Palladium-Catalyzed Decarboxylative Couplings of 2-(2-Azaaryl)acetates with Aryl Halides and Triflates
作者:Rui Shang、Zhi-Wei Yang、Yan Wang、Song-Lin Zhang、Lei Liu
DOI:10.1021/ja107103b
日期:2010.10.20
Pd-catalyzed decarboxylative cross-couplings of 2-(2-azaaryl)acetates with arylhalides and triflates have been discovered. This reaction is potentially useful for the synthesis of some functionalized pyridines, quinolines, pyrazines, benzoxazoles, and benzothiazoles. Theoretical analysis shows that the nitrogen atom at the 2-position of the heteroaromatics directly coordinates to Pd(II) in the decarboxylation
Efficient Selenium-Catalyzed Selective C(sp<sup>3</sup>)−H Oxidation of Benzylpyridines with Molecular Oxygen
作者:Weiwei Jin、Poonnapa Zheng、Wing-Tak Wong、Ga-Lai Law
DOI:10.1002/adsc.201601065
日期:2017.5.2
An efficient selenium‐catalyzed direct oxidation of benzylpyridines in aqueous DMSO has been successfully developed by using molecularoxygen as the oxidant. A variety of benzoylpyridines with broad functional group tolerance were obtained in modest to excellent yields and with exclusive chemoselectivity.
Synthesis of Aryl(di)azinyl Ketones through Copper- and Iron-catalyzed Oxidation of the Methylene Group of Aryl(di)azinylmethanes
作者:Johan De Houwer、Kourosch Abbaspour Tehrani、Bert U. W. Maes
DOI:10.1002/anie.201108540
日期:2012.3.12
Sustainable Oxidations: An oxidation method to transform aryl(di)azinylmethanes into aryl(di)azinylketones is described. Base metals (copper and iron) as catalysts in combination with O2 as the oxidant are used, which makes this method sustainable. The utility of this method is illustrated by the synthesis of 6‐(4‐methylbenzoyl)pyridine‐2‐carbaldehyde, which is an intermediate in the preparation of
An iron-catalyzed aerobic oxidation of (alkyl)(aryl)azinylmethanes has been developed leading to tertiary alcohols in moderate to good yields. Hock rearrangement was identified as a major side reaction leading to a complex mixture of undesired products. Addition of thiourea sometimes allows inhibiting this side reaction and steers the reaction towards the desired products.
whereas KOt-Bu promotes the formation of the meso-tetraarylethanes. Interestingly, the presence of excess KOt-Bu generates the (E)-tetraarylethenes as the only product. A highly efficient and base-controlled diastereoselective synthesis of tetraarylethanes through copper-catalyzed dehydrogenative homocoupling of readily available 2-benzylpyridines is reported. Various dl- and meso-tetraarylethanes were
专用于M. Periyasamy教授在他的65之际个生日。 抽象的 据报道,通过容易获得的2-苄基吡啶的铜催化的脱氢均偶联反应,可以高效地进行碱控制的非对映选择性合成四芳基乙烷。通过该新方案非对映体合成了各种dl-和内消旋-四芳基乙烷,其中碱起主要调节剂的作用:格氏试剂选择性地提供了C 2异构体,而KO t -Bu促进了内消旋-四芳基乙烷的形成。有趣的是,过量的KO t -Bu的存在产生了(E)-四芳基醚作为唯一产物。 据报道,通过容易获得的2-苄基吡啶的铜催化的脱氢均偶联反应,可以高效地进行碱控制的非对映选择性合成四芳基乙烷。通过该新方案非对映体合成了各种dl-和内消旋-四芳基乙烷,其中碱起主要调节剂的作用:格氏试剂选择性地提供了C 2异构体,而KO t -Bu促进了内消旋-四芳基乙烷的形成。有趣的是,过量的KO t -Bu的存在产生了(E)-四芳基醚作为唯一产物。