Phosphine-Catalyzed Formal Oxa-[4 + 2] Annulation Employing Nitroethylene and Enones: Enantioselective Synthesis of Dihydropyrans
作者:Zhichao Jin、Huanzhen Ni、Bo Zhou、Wenrui Zheng、Yixin Lu
DOI:10.1021/acs.orglett.8b02519
日期:2018.9.7
The first phosphine-catalyzed enantioselective formal oxa-[4 + 2] reaction between nitroethylene and α-cyano-α,β-unsaturated ketones has been developed. In the presence of a dipeptide-based phosphine catalyst and achiral Brønsted acid additives, highly functionalized 3,4-dihydro-2H-pyrans were obtained with excellent enantio- and diastereoselectivities.
已经开发出了第一个膦催化的硝基乙烯与α-氰基-α,β-不饱和酮之间的对映体选择性oxa- [4 + 2]反应。在基于二肽的膦催化剂和非手性布朗斯台德酸添加剂的存在下,获得了具有出色的对映选择性和非对映选择性的高度官能化的3,4-二氢-2 H-吡喃。