Synthesis of two (S)-indoline-based chiral auxiliaries and their use in diastereoselective alkylation reactions
Responsible organisation
2006 (English)In: Tetrahedron: asymmetry, ISSN 0957-4166, E-ISSN 1362-511X, Vol. 17, no 13, p. 1952-1957Article in journal (Refereed) Published
Abstract [en]
Two chiral auxiliaries, 2-[(S)-indolin-2-yl]propan-2-ol 1a and (S)-2-(2-methoxypropan-2-yl)indoline 1b, were synthesised from enantiomerically pure (S)-indoline-2-carboxylic acid 3. High diastereoselectivities in alkylations of enolates of the propanoylamides derived from the two auxiliaries are presented. Surprisingly, both auxiliaries induced the same selectivity at the newly created stereogenic centre. The benzyl bromide and n-butyl iodide alkylation reactions showed diastereomeric ratios that were moderate (81:19) to very good (96:4) and with very good yields (86-98%). When LiCl was used as an enolate coordinating agent, in the benzylation of the enolate from propanoylated auxiliary 1a, a very high crude diastereomeric ratio was obtained (99.7:0.3).
Place, publisher, year, edition, pages
2006. Vol. 17, no 13, p. 1952-1957
Keywords [en]
Synthesis chiral auxiliaries diastereoselective alkylation reactions
National Category
Chemical Sciences
Identifiers
URN: urn:nbn:se:miun:diva-3876DOI: 10.1016/j.tetasy.2006.07.002ISI: 000240242300005Scopus ID: 2-s2.0-33746979728Local ID: 4196OAI: oai:DiVA.org:miun-3876DiVA, id: diva2:28908
2008-09-302008-09-302017-12-12Bibliographically approved