Et3B/Et2AlCl/O2‐Mediated Radical Coupling Reaction between α‐Alkoxyacyl Tellurides and 2‐Hydroxybenzaldehyde Derivatives. Issue 22 (16th October 2020)

• Record Type: Journal Article
• Authors: Nagatomo, Masanori; Zhang, Keshu; Fujino, Haruka; Inoue, Masayuki
• Is Part Of: Chemistry, an Asian journal. Volume 15:Issue 22(2020)
• Page Start: 3820
• Page End: 3824
• Publication Date: 2020-10-16
• Subjects: C−C coupling -- radical reactions -- oxygen heterocycles -- tellurium -- aldehydes; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/asia.202001090
• Languages: English
• ISSNs: 1861-4728

Abstract

Abstract: A newly devised radical‐based strategy enabled coupling between multiply oxygenated α‐alkoxyacyl tellurides and 2‐hydroxybenzaldehyde derivatives. A reagent combination of Et3 B, Et2 AlCl, and O2 promoted the formation of the α‐alkoxy carbon radical from the α‐alkoxyacyl telluride and the addition of the radical to the carbonyl group of 2‐hydroxybenzaldehyde. The reaction chemo‐ and stereoselectively forged the hindered C−C bond between two oxygen‐functionalized carbons at ambient temperature. The method was applied to the preparation of 12 coupling adducts with three to six contiguous stereocenters and to the concise synthesis of an antitumor compound, LLY‐283. Abstract : New Et3 B/Et2 AlCl/O2 ‐mediated radical conditions realized coupling reactions between various α‐alkoxyacyl tellurides and 2‐hydroxybenzaldehyde derivatives. Et3 B and O2 initiated the formation of the α‐alkoxy radical from the α‐alkoxyacyl telluride, while Et2 AlCl acted as both a Lewis acid to activate the C=O bond and a radical terminator of the unstable oxyl radical. This mild, powerful method was effectively used to synthesize antitumor compound LLY‐283.