International Scientific and Technological Cooperation Base of Chiral Chemistry, Henan University, Kaifeng, Henan 475004, P. R. China.
Division of Chemistry and Biological Chemistry, Nanyang Technological University, Singapore 637371.
J Am Chem Soc. 2021 Mar 17;143(10):4024-4031. doi: 10.1021/jacs.1c01073. Epub 2021 Mar 2.
A novel enantioselective protonation protocol that is triggered by reductive cross coupling of olefins is reported. When under cooperative photoredox and chiral hydrogen-bonding catalytic conditions and using a terminal reductant, various α-branched vinylketones with diverse vinylazaarenes could provide important enantioenriched azaarene derivatives containing tertiary stereocenters at their remote δ-position with high yields and enantioselectivities. This reaction system is also suitable for α-branched vinylazaarenes, thus successfully assembling elusive 1,4-stereocenters. The convenient late-stage modifications of products, especially the formation of remote ε-tertiary and ε-heteroquaternary carbon stereocenters, further highlight the important synthetic value of this method. Control experiments and density functional theory (DFT) calculations were conducted to elucidate the plausible reaction mechanism and origins of regioselectivity and stereoselectivity.
报道了一种新颖的对映选择性质子化方案，该方案由烯烃的还原交叉偶联引发。在光还原和手性氢键催化条件下，并使用末端还原剂时，各种具有不同乙烯氮杂芳烃的α-支化乙烯基酮可以以高产率和对映选择性提供在远程 δ-位含有叔立体中心的重要对映富集氮杂芳烃衍生物。该反应体系也适用于α-支化的乙烯氮杂芳烃，从而成功地组装了难以捉摸的 1,4-立体中心。产物的方便的后期修饰，特别是远程 ε-叔碳和 ε-杂季碳立体中心的形成，进一步突出了该方法的重要合成价值。进行了控制实验和密度泛函理论（DFT）计算，以阐明可能的反应机理以及区域选择性和立体选择性的起源。
