Ti-catalyzed ring-opening oxidative amination of methylenecyclopropanes with diazenes.
Ti-catalyzed ring-opening oxidative amination of methylenecyclopropanes with diazenes.
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DOI：
10.1039/d0sc01998d
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发表时间：
2020-06-23
期刊：
影响因子：
8.4
通讯作者：
Tonks IA
中科院分区：
文献类型：
--
作者：
Beaumier EP;Ott AA;Wen X;Davis-Gilbert ZW;Wheeler TA;Topczewski JJ;Goodpaster JD;Tonks IA
报道了Py_3TiCl_2（NR）配合物催化亚甲基环丙烷与二氮烯开环氧化胺化反应。该反应选择性地产生支链α-亚甲基亚胺，而不是难以通过其他方法获得的直链α，β-不饱和亚胺。产物可以作为亚胺分离或以良好的产率水解成相应的酮。通过密度泛函理论的机理研究表明，这些产物的区域选择性来自Curtin-Hammett动力学方案，其中螺环[2 + 2]氮杂钛酸环丁烯中间体的可逆β-碳消除之后是所得金属镧的选择性决定的β-氢消除。探索这些支链α-亚甲基亚胺产物的进一步官能化，证明它们作为结构单元的实用性。报道了Py_3TiCl_2（NR）配合物催化亚甲基环丙烷与二氮烯开环氧化胺化反应。
The ring-opening oxidative amination of methylenecyclopropanes (MCPs) with diazenes catalyzed by py3TiCl2(NR) complexes is reported. This reaction selectively generates branched α-methylene imines as opposed to linear α,β-unsaturated imines, which are difficult to access via other methods. Products can be isolated as the imine or hydrolyzed to the corresponding ketone in good yields. Mechanistic investigation via density functional theory suggests that the regioselectivity of these products results from a Curtin–Hammett kinetic scenario, where reversible β-carbon elimination of a spirocyclic [2 + 2] azatitanacyclobutene intermediate is followed by selectivity-determining β-hydrogen elimination of the resulting metallacycle. Further functionalizations of these branched α-methylene imine products are explored, demonstrating their utility as building blocks. The ring-opening oxidative amination of methylenecyclopropanes (MCPs) with diazenes catalyzed by py3TiCl2(NR) complexes is reported.