Organocatalysis "on water". Regioselective [3 + 2]-cycloaddition of nitrones and allenolates

3 pages, 2 tables, 2 schemes.-- PMID: 17009467 [PubMed].The first example of a regioselective and organocatalyzed 1,3-dipolar cycloaddition reaction between conjugated alkynoates and nitrones "on water" is described.This research was supported by the Spanish Ministerio de Educación y Ciencia and the European Regional Development Fund (CTQ2005-09074-C02-02) and the Instituto Canario de Investigación del Cáncer (ISCiii, RTICCC ICI-GI-Na10/200). D.T. thanks CSIC for an I3P postdoctoral position. D. G.-C. thanks MEC for an FPI grant