Regioselective electrophilic formylation - 3-substituted thiophenes as a case study

Authors
Meth-Cohn, O Ashton, M
Citation
O. Meth-cohn et M. Ashton, Regioselective electrophilic formylation - 3-substituted thiophenes as a case study, TETRAHEDR L, 41(15), 2000, pp. 2749-2752
Citations number
3
Categorie Soggetti
Chemistry & Analysis","Organic Chemistry/Polymer Science
Journal title
TETRAHEDRON LETTERS
ISSN journal
00404039 → ACNP
Volume
41
Issue
15
Year of publication
2000
Pages
2749 - 2752
Database
ISI
SICI code
0040-4039(20000408)41:15<2749:REF-3T>2.0.ZU;2-G
Abstract
A variety of methods for regioselective formylation have been examined and exemplified with 3-methylthiophene. Optimal yields and regioselectivity for 2-formylation were obtained with N-formylpyrrolidine (11:1) although up to a 46:1 ratio could be obtained with MeOCHCl2:TiCl4, albeit in lower yield. Optimal 5-formylation (1:1.5) was obtained when using N-formylindoline:(CO Cl)(2). (C) 2000 Elsevier Science Ltd. All rights reserved.