Formal Asymmetric Cycloaddition of Activated α,β-Unsaturated Ketones with α-Diazomethylphosphonate Mediated by a Chiral Silver SPINOL Phosphate Catalyst
作者:Bo Zheng、Haohua Chen、Lei Zhu、Xiqiang Hou、Yan Wang、Yu Lan、Yungui Peng
DOI:10.1021/acs.orglett.8b03436
日期:2019.2.1
nonspiro-phosphonylpyrazolines via an asymmetric formal 1,3-dipolar cycloaddition reaction of α-diazomethylphosphonate with activated, acyclic α,β-unsaturated ketones, bearing an additional nitrile electron-withdrawing group, has been developed, utilizing an in situ generated chiral silver phosphate catalyst, affording excellent stereoselectivities (up to 98% ee, 99:1 dr) and yields (up to 95%). A stepwise
已开发出一种有效的方法,该方法可通过α-重氮甲基膦酸酯与带有额外腈吸电子基团的活化,无环α,β-不饱和酮的不对称形式1,3-偶极环加成反应制备高度官能化的手性非螺膦酰基吡唑啉,利用原位生成的手性磷酸银催化剂,可提供出色的立体选择性(ee高达98%,dr的99:1 )和收率(高达95%)。基于密度泛函M11的计算,提出了一种逐步机制。