enantioselective Pd(II)-catalyzed intramolecularoxidative amination reaction was developed utilizing the commercially available chiral X-type ligand (1S)-(+)-camphorsulfonic acid. The Wacker-type cyclization produced chiral indoline products with enantioselectivies up to 45% ee. Electronic structure calculations employing density functional theory support a trans-aminopalladation mechanism.
Catalytic, Enantioselective, Intramolecular Sulfenoamination of Alkenes with Anilines
作者:Scott E. Denmark、Hyung Min Chi
DOI:10.1021/acs.joc.7b00391
日期:2017.4.7
A method for the catalytic, enantioselective, intramolecular sulfenoamination of alkenes with aniline nucleophiles has been developed. The method employs a chiral, Lewis basic selenophosphoramide catalyst and a Brønsted acid co-catalyst to promote stereocontrolled C-N and C-S bond formation by activation of an achiral sulfenylating agent. Benzoannulated nitrogen-containing heterocycles such as indolines
Acceptorless dehydrogenative amination of alkenes for the synthesis of N-heterocycles
作者:Jia-Lin Tu、Wan Tang、Shi-Hui He、Ma Su、Feng Liu
DOI:10.1007/s11426-022-1241-x
日期:2022.7
Catalytic amination of alkenes is one of the most attractive reactions for the construction of complex heterocycles with nitrogen centers. Herein, we present that synergistic photoredox and cobaloxime catalysis allows for highly efficient and mild dehydrogenative reactions between various NH nucleophiles and di-, tri-, and tetrasubstituted alkenes in the absence of external oxidants, thus enabling
烯烃的催化胺化是构建具有氮中心的复杂杂环最有吸引力的反应之一。在这里,我们提出协同光氧化还原和钴肟催化允许在没有外部氧化剂的情况下,各种 NH 亲核试剂与二、三和四取代烯烃之间进行高效和温和的脱氢反应,从而能够获得一系列N杂环。值得注意的是,含Z和E烯烃的N杂环都是可以得到的。机理研究表明Z-肉桂基衍生物可以通过光催化E to Z通过能量转移过程进行烯烃异构化。此外,我们发现缓慢的能量转移可以抑制E到Z烯烃异构化过程,从而提供具有E选择性的肉桂基衍生物。我们的结果突出了使用双光氧化还原和钴肟催化反应产生多种N-杂环的好处。
Highly Site-Selective Oxidative Cyclization of Ene-ynamides via Non-Noble-Metal Catalysis: Access to Functionalized Lactams
Herein, an unprecedented non-noble-metal-catalyzed oxidation/cyclization of ene-ynamides is developed, allowing the synthesis of diversely functionalized lactams in moderate to good yields with excellent diastereoselectivities without the observation of typical cyclopropanation products. In combination with Ellman’s tert-butylsulfinimine chemistry, chiral γ-lactams containing three contiguous stereocenters