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.
The first example of benzylic C—H triflylation was accomplished with pyridine as a directing group. The reaction of various 2‐benzylpyridines and (CF3SO2)2O in the presence of NEt3 in CH2Cl2 proceeded smoothly to afford the corresponding benzyl triflones in moderate to high yields.
用吡啶作为指导基团完成苄基CHF3-三氟甲基化的第一个实例。在NEt 3存在下,各种2-苄基吡啶和(CF 3 SO 2)2 O在CH 2 Cl 2中的反应顺利进行,以中等至高收率提供了相应的苄基三氟甲酮。
Versatile C(sp<sup>2</sup>)−C(sp<sup>3</sup>) Ligand Couplings of Sulfoxides for the Enantioselective Synthesis of Diarylalkanes
作者:William M. Dean、Mindaugas Šiaučiulis、Thomas E. Storr、William Lewis、Robert A. Stockman
DOI:10.1002/anie.201602264
日期:2016.8.16
The reaction of chiral (hetero)aryl benzyl sulfoxides with Grignard reagents affords enantiomerically pure diarylalkanes in up to 98 % yield and greater than 99.5 % enantiomeric excess. This ligand coupling reaction is tolerant to multiple substitution patterns and provides access to diverse areas of chemical space in three operationally simple steps from commercially available reagents. This strategy
Direct aerobic oxidation of 2-benzylpyridines in a gas–liquid continuous-flow regime using propylene carbonate as a solvent
作者:Bartholomäus Pieber、C. Oliver Kappe
DOI:10.1039/c2gc36896j
日期:——
The use of high-temperature/pressure gasâliquid continuous flow conditions dramatically enhances the iron-catalyzed aerobic oxidation of 2-benzylpyridines to their corresponding ketones. Pressurized air serves as a readily available oxygen source and propylene carbonate as a green solvent in this radically intensified preparation of synthetically valuable 2-aroylpyridines.