A new diastereo- and enantioselective copper-catalyzed conversion of alkynyl epoxides into alpha-allenic alcohols.

Authors
Bertozzi, F Crotti, P Macchia, F Pineschi, M Arnold, A Feringa, BL
Citation
F. Bertozzi et al., A new diastereo- and enantioselective copper-catalyzed conversion of alkynyl epoxides into alpha-allenic alcohols., TETRAHEDR L, 40(26), 1999, pp. 4893-4896
Citations number
17
Categorie Soggetti
Chemistry & Analysis","Organic Chemistry/Polymer Science
Journal title
TETRAHEDRON LETTERS
ISSN journal
00404039 → ACNP
Volume
40
Issue
26
Year of publication
1999
Pages
4893 - 4896
Database
ISI
SICI code
0040-4039(19990625)40:26<4893:ANDAEC>2.0.ZU;2-9
Abstract
Chiral copper complexes of BINOL- and TADDOL derived phosphorus amidites pr oved to be highly effective catalysts for the alkylation of alkynyl epoxide s with dialkylzinc reagents. The corresponding alpha-allenol reaction produ cts (S(N)2'-pathway) were obtained with good to excellent regio- and diaste reoselectivity. The e.e. values obtained for this reaction were in the rang e of 26-38 %. A number of different Cu(II)-complexes were screened as possi ble catalysts and the results obtained indicate a complete control of the d iastereoselectivity with an easy access to both enantioenriched syn and ant i-alpha-allenols. (C) 1999 Elsevier Science Ltd. All rights reserved.