Chemistry–A European Journal

Protecting??Group??Free Total Synthesis of Isoquinoline Alkaloids by Nickel??Catalyzed Annulation of o??Halobenzaldimine with an Alkyne as the Key Step

RP Korivi, CH Cheng

Index: Korivi, Rajendra Prasad; Cheng, Chien-Hong Chemistry - A European Journal, 2010 , vol. 16, # 1 p. 282 - 287

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Citation Number: 48

Abstract

Abstract An efficient short total synthesis of benzo [c] phenanthridine alkaloids including oxyavicine, oxynitidine, and oxysanguinarine is described. Thus, N-methyl-o- bromobenzaldimines 1 b–d undergo regioselective cyclization with 4-(benzo [d][1, 3] dioxol- 5-yl) but-3-yn-1-ol (2 b) in the presence of [Ni (cod) 2](cod= 1, 5-cyclooctadiene). In situ oxidation of the resultant isoquinolinium salts gives isoquinolinone derivatives 5 b–d with ...