Copper-catalyzed [2+3]-annulation of N–H imines with vinyl azides: access to polyaryl 2<i>H</i>-imidazoles
作者:Zhongzhi Zhu、Hanze Lin、Baihui Liang、Junjie Huang、Wanyi Liang、Lu Chen、Yubing Huang、Xiuwen Chen、Yibiao Li
DOI:10.1039/c9cc10042c
日期:——
A practical method for the synthesis of 2H-imidazoles via a [2+3] annulation of N-H imines with vinylazides using a copper catalyst is developed. In this conversion, environmentally friendly oxygen is used as the sole oxidant and N2 and H2O are the only by-products. The catalytic transformation, operating under mild conditions, is operationally simple and is considered as a readily available catalytic
Cobalt-Catalyzed, N–H Imine-Directed Hydroarylation of Styrenes
作者:Wengang Xu、Naohiko Yoshikai
DOI:10.1021/acs.orglett.8b00164
日期:2018.3.2
A cobalt-catalyzed, N–H imine-directed hydroarylation reaction of styrenes is reported. A variety of diaryl and aryl alkyl N–H imines participated in the reaction to afford the corresponding branched adducts in good yield and regioselectivity. Interestingly, unsymmetrical diaryl imines with modest electronic biases reacted regioselectively at one of the aryl rings. Furthermore, the branched selectivity
Ruthenium(II)/N-Heterocyclic Carbene Catalyzed [3+2] Carbocyclization with Aromatic NH Ketimines and Internal Alkynes
作者:Jing Zhang、Angel Ugrinov、Pinjing Zhao
DOI:10.1002/anie.201209031
日期:2013.6.24
which occurs at ambient temperature, in the absence of oxidants or other metal salts, and in nonpolar solvents. A proposed mechanism involves imine‐directed activation of an aromatic CH bond, alkyne insertion, and carbocyclization by intramolecular imine insertion into Ru–alkenyl linkages.
方便且高效:使用标题反应合成茚胺,该反应在环境温度、不存在氧化剂或其他金属盐的情况下以及在非极性溶剂中发生。提出的机制涉及芳族 C - H 键的亚胺定向活化、炔烃插入以及通过分子内亚胺插入 Ru-烯基键进行碳环化。
Asymmetric Organocatalytic Formal Aza-Michael Addition of Ammonia to Nitroalkenes
The formal addition of ammonia to nitroalkenes, affording optically active β‐amino nitro compounds in high yields and enantioselectivities, is presented (see scheme). The approach is based on a novel thiourea‐catalyzed aza‐Michael reaction, by which benzophenone imine serves as a masked ammonia equivalent, which is released by hydrolysis.
Tertiary Carbinamine Synthesis by Rhodium-Catalyzed [3+2] Annulation of N-Unsubstituted Aromatic Ketimines and Alkynes
作者:Zhong-Ming Sun、Shuo-Ping Chen、Pinjing Zhao
DOI:10.1002/chem.200902814
日期:2010.2.22
A convenient and waste‐free synthesis of indene‐based tertiary carbinamines by rhodium‐catalyzed imine/alkyne [3+2] annulation is described. Under the optimized conditions of 0.5–2.5 mol % [(cod)Rh(OH)}2] (cod=1,5‐cyclooctadiene) catalyst, 1,3‐bis(diphenylphosphanyl)propane (DPPP) ligand, in toluene at 120 °C, N‐unsubstituted aromatic ketimines and internal alkynes were coupled in a 1:1 ratio to form