Ring-closing iodoamination of homoallylic amines for the synthesis of polysubstituted pyrrolidines: application to the asymmetric synthesis of (-)-codonopsinine

Journal article

Ring-closing iodoamination of (E)-configured, N-α-methyl-p- methoxybenzyl protected homoallylic amines upon treatment with I 2 and NaHCO 3 in MeCN occurs with concomitant loss of the N-α-methyl-p-methoxybenzyl group to give 3-iodopyrrolidines in >99:1 dr. This transformation was used as one of the key steps in the total asymmetric synthesis of (-)-codonopsinine, which was achieved in seven steps (from commercially available tert-butyl crotonate) in 5% overall yield and >99:1 dr. © 2012 Elsevier Ltd. All rights reserved.

Authors: Davies, S; Lee, J; Roberts, P; Thomson, J; West, C

• Publication status: Published
• Journal: TETRAHEDRON
• Volume: 68
• Issue: 22
• Pages: 4302-4319
• Publication date: 2012-06-03
• DOI: 10.1016/j.tet.2012.03.045
• EISSN: 1464-5416
• ISSN: 0040-4020
• Language: English
• Keywords: (-)-Codonopsinine; Ring-closing iodoamination; Lithium amide; Pyrrolidine