Palladium-catalyzed carbonylation of benzylic ammonium salts to amides and esters <i>via</i> C–N bond activation
作者:Weijie Yu、Shuwu Yang、Fei Xiong、Tianxiang Fan、Yan Feng、Yuanyuan Huang、Junkai Fu、Tao Wang
DOI:10.1039/c8ob00488a
日期:——
An efficient palladium-catalyzed carbonylation reaction of readily available quaternary ammonium salts with CO is reported for the first time to afford arylacetamides and arylacetic acid esters via benzylic C–N bond cleavage. This protocol features mild reaction conditions under atmospheric pressure of CO, a redox-neutral process without an additional oxidant, and a broad substrate scope for various
visible-light photoredox catalysis. A variety of tetraalkyl ammonium salts, bearing primary, secondary, and tertiary C-N bonds, undergo selective couplings with aldehydes/ketone and CO2. Notably, the in situ generated byproduct, trimethylamine, is efficiently utilized as the electron donor. Moreover, this protocol exhibits mild reaction conditions, low catalyst loading, broad substrate scope, good
两个亲电子试剂之间的交叉亲电子试剂偶联是在化学计量外部还原剂存在下生成 CC 键的有效且经济的方法。在此,我们报告了一种通过可见光光氧化还原催化实现第一个无外部还原剂的交叉亲电子偶联的新策略。各种带有伯、仲和叔 CN 键的四烷基铵盐与醛/酮和 CO2 进行选择性偶联。值得注意的是,原位生成的副产物三甲胺被有效地用作电子供体。此外,该协议表现出温和的反应条件、低催化剂负载、广泛的底物范围、良好的官能团耐受性和容易的可扩展性。机理研究表明,苄基自由基和阴离子可能是通过光催化产生的关键中间体,
Transition metal-free coupling reactions of benzylic trimethylammonium salts with di(hetero)aryl disulfides and diselenides
A new protocol was developed to synthesize (enantioenriched) thioethers and selenoethersfrom (chiral) benzylic trimethylammonium salts and di(hetero)aryl disulfides or diselenides. These syntheses were promoted by the presence of weak base and did not require the use of any transition metal, and resulted in the target products with good to excellent yields (72–94%). Using quaternary ammonium salts
A palladium catalyzed reductive aminocarbonylation of benzylic ammonium triflates with nitroarenes for the synthesis of phenylacetamides was developed. Using Pd(acac)2/DPPF catalystsystem, a range of different substituted phenylacetamides were prepared in moderate to good yields from benzylic ammonium triflates and nitroarenes through Csp3−N bond cleavage. A variety of alkyl, aryl, and halide substituents
Making Dimethylamino a Transformable Directing Group by Nickel-Catalyzed CN Borylation
作者:Hua Zhang、Shinya Hagihara、Kenichiro Itami
DOI:10.1002/chem.201503596
日期:2015.11.16
The dimethylamino (Me2N) group is arguably the most versatile functional group capable of highly efficient and site‐selective directed aromatic functionalizations at the ortho‐, meta‐, and para‐positions depending on reaction conditions. While the repertoire of Me2N‐directed reactions is growing at a rapid pace, the lack of a general method to transform this group to other functionalities hampers its