Bifunctional Phosphonium Salt Directed Enantioselective Formal [4 + 1] Annulation of Hydroxyl-Substituted <i>para</i>-Quinone Methides with α-Halogenated Ketones
作者:Jian-Ping Tan、Peiyuan Yu、Jia-Hong Wu、Yuan Chen、Jianke Pan、Chunhui Jiang、Xiaoyu Ren、Hong-Su Zhang、Tianli Wang
DOI:10.1021/acs.orglett.9b02560
日期:2019.9.20
A highly diastereo- and enantioselective [4 + 1] cycloaddition of para-quinone methides to α-halogenated ketones was realized by bifunctional phosphonium salt catalysis, furnishing functionalized 2,3-dihydrobenzofurans in high yields and excellent stereoselectivities (>20:1 dr and up to >99.9% ee). Mechanistic observations suggested that the reaction underwent a cascade intermolecular substitution/intramolecular
Enantioselective γ-Addition-Driven Cascade of β,γ-Unsaturated Ketones by Ion-Pair Catalysis: Access to Chiral 1,3-Dioxolochroman Scaffolds
作者:Xuemei Wang、Liang Zhou、Hongkui Zhang、Xiaoyu Ren、Guowei Gao、Tianli Wang
DOI:10.1021/acs.orglett.1c03567
日期:2022.1.14
A highlyenantioselective γ-addition-driven cascade of β,γ-unsaturated carbonyl compounds by bifunctional ion-pair catalysis has been developed. With this protocol, a range of functionalized chiral 1,3-dioxolochroman derivatives were prepared in high yields with superior stereoselectivities (>99% ee and >20:1 dr). The utility of this method was demonstrated by one-pot synthesis, scaled-up preparation
作者:Fangrui Zhong、Youqing Wang、Xiaoyu Han、Kuo-Wei Huang、Yixin Lu
DOI:10.1021/ol103145g
日期:2011.3.18
A series of novel bifunctional phosphine sulfonamide organic catalysts were designed and readily prepared from natural amino acids, and they were utilized to promote enantioselective aza-Morita-Baylis-Hillman (MBH) reactions. L-Threonine-derived phosphine-sulfonamide 9b was found to be the most efficient catalyst, affording the desired aza-MBH adducts in high yields and with excellent enantioselectivities.