Cobalt-Catalyzed C–H Cyanation of (Hetero)arenes and 6-Arylpurines with <i>N</i>-Cyanosuccinimide as a New Cyanating Agent
作者:Amit B. Pawar、Sukbok Chang
DOI:10.1021/ol503680d
日期:2015.2.6
A cobalt-catalyzed C–H cyanation reaction of arenes has been developed using N-cyanosuccinimide as a new electrophilic cyanating agent. The reaction proceeds with high selectivity to afford monocyanated products with excellent functional group tolerance. Substrate scope was found to be broad enough to include a wide range of heterocycles including 6-arylpurines.
Manganese(I)-Catalyzed Direct C–H Allylation of Arenes with Allenes
作者:Shi-Yong Chen、Qingjiang Li、Honggen Wang
DOI:10.1021/acs.joc.7b02220
日期:2017.10.20
Polysubstituted allyl groups, for example, the prenyl group, are valuable synthetic handles and widely encountered in bioactive compounds. Reported herein is a manganese(I)-catalyzeddirectC–H coupling with allenes for the efficient assembly of allylated arenes. The protocol offers an extremely high level of atom-economy and is particularly suited for the introduction of 1,1-disubstitiuted allyl groups
Enantioselective Synthesis of α-(Hetero)aryl Piperidines through Asymmetric Hydrogenation of Pyridinium Salts and Its Mechanistic Insights
作者:Bo Qu、Hari P. R. Mangunuru、Sergei Tcyrulnikov、Daniel Rivalti、Olga V. Zatolochnaya、Dmitry Kurouski、Suttipol Radomkit、Soumik Biswas、Shuklendu Karyakarte、Keith R. Fandrick、Joshua D. Sieber、Sonia Rodriguez、Jean-Nicolas Desrosiers、Nizar Haddad、Keith McKellop、Scott Pennino、Heewon Lee、Nathan K. Yee、Jinhua J. Song、Marisa C. Kozlowski、Chris H. Senanayake
DOI:10.1021/acs.orglett.8b00067
日期:2018.3.2
α-heteroaryl piperidines is reported. The key step is an iridium-catalyzed asymmetric hydrogenation of substituted N-benzylpyridinium salts. High levels of enantioselectivity up to 99.3:0.7 er were obtained for a range of α-heteroaryl piperidines. DFT calculations support an outersphere dissociative mechanism for the pyridinium reduction. Notably, initial protonation of the final enamine intermediate
报道了 α-芳基和 α-杂芳基哌啶的对映选择性合成。关键步骤是取代的N-苄基吡啶鎓盐的铱催化不对称氢化。一系列 α-杂芳基哌啶获得了高达 99.3:0.7 er 的高水平对映选择性。DFT 计算支持吡啶还原的外层解离机制。值得注意的是,最终烯胺中间体的初始质子化决定了转化的立体化学结果,而不是所得亚胺中间体的氢化物还原。