title: Total Synthesis of Dimeric HPI Alkaloids.
abstract: In this paper, we report a full account of the synthesis of dimeric hexahydropyrroloindole alkaloids and its analogues. The key feature of our new strategy is the novel catalytic copper (10 %) mediated intramolecular arylations of o-haloanilides followed by intermolecular oxidative dimerization of the resulting oxindoles in one pot. This sequential reaction leads to the key intermediates for the synthesis of (+)-chimonanthine, (+)-folicanthine, (-)-calycanthine and (-)-ditryptophenaline. In the presence of catalytic amount of cuprous iodide (10 %), an intramolecular arylation of o-haloanilides followed by an intermolecular oxidative dimerization of the resulting oxindoles leads to a common intermediate for the synthesis of (+)-chimonanthine, (+)-folicanthine and (-)-calycanthine. Based on this cascade sequence, we also developed a flexible strategy towards the asymmetric syntheses of dimeric HPI alkaloids (-)-ditryptophenaline and its analogues.
authors.affiliation: Key Laboratory of Medicinal Chemistry for Natural Resource (Yunnan University), Ministry of Education, School of Chemical Science and Technology, Yunnan University, Kunming, 650091, People's Republic of China.
authors.forename: Xianfu
authors.initials: X
authors.lastname: Shen
authors.affiliation: Key Laboratory of Medicinal Chemistry for Natural Resource (Yunnan University), Ministry of Education, School of Chemical Science and Technology, Yunnan University, Kunming, 650091, People's Republic of China.
authors.forename: Yongyun
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Key Laboratory of Medicinal Chemistry for Natural Resource (Yunnan University), Ministry of Education, School of Chemical Science and Technology, Yunnan University, Kunming, 650091, People's Republic of China.
authors.forename: Yongkai
authors.initials: Y
authors.lastname: Xi
authors.affiliation: Key Laboratory of Medicinal Chemistry for Natural Resource (Yunnan University), Ministry of Education, School of Chemical Science and Technology, Yunnan University, Kunming, 650091, People's Republic of China.
authors.forename: Jingfeng
authors.initials: J
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Medicinal Chemistry for Natural Resource (Yunnan University), Ministry of Education, School of Chemical Science and Technology, Yunnan University, Kunming, 650091, People's Republic of China. zhanghb@ynu.edu.cn.
authors.forename: Hongbin
authors.initials: H
authors.lastname: Zhang
keywords: Alkaloids; Copper catalyzed reaction; Hexahydropyrroloindole; Oxidative dimerization; Total synthesis