TY - JOUR
T1 - Diels-Alder reactions of 2-oxazolidinone dienes in polar solvents using catalysis or non-conventional energy sources
AU - Fuentes, Aydeé
AU - Martínez-Palou, Rafael
AU - Jiménez-Vázquez, Hugo A.
AU - Delgado, Francisco
AU - Reyes, Alicia
AU - Tamariz, Joaquín
PY - 2005/2
Y1 - 2005/2
N2 - The (Z)-N-substituted 4-methylene-5-propylidene-2-oxazolidinone dienes were prepared by a one-step synthesis, starting from 2,3-hexanedione and isocyanates. Diels-Alder cycloadditions of these dienes were carried out in the presence of the dienophiles methyl vinyl ketone, methyl propiolate, and a captodative olefin, under conditions such as solvents of high polarity, Lewis acid catalysis, and non-conventional energy sources. The reactions carried out either with mixtures of H2O/MeOH or under BF3· Et2O catalysis yielded the highest regio- and stereoselectivities. The use of ionic liquids, microwaves, and ultrasound did not significantly increase the selectivity.
AB - The (Z)-N-substituted 4-methylene-5-propylidene-2-oxazolidinone dienes were prepared by a one-step synthesis, starting from 2,3-hexanedione and isocyanates. Diels-Alder cycloadditions of these dienes were carried out in the presence of the dienophiles methyl vinyl ketone, methyl propiolate, and a captodative olefin, under conditions such as solvents of high polarity, Lewis acid catalysis, and non-conventional energy sources. The reactions carried out either with mixtures of H2O/MeOH or under BF3· Et2O catalysis yielded the highest regio- and stereoselectivities. The use of ionic liquids, microwaves, and ultrasound did not significantly increase the selectivity.
KW - Ab initio calculations
KW - Cycloadditions
KW - Ionic liquids
KW - Microwaves
KW - Solvent effect
UR - http://www.scopus.com/inward/record.url?scp=13444261009&partnerID=8YFLogxK
U2 - 10.1007/s00706-004-0244-0
DO - 10.1007/s00706-004-0244-0
M3 - Artículo
SN - 0026-9247
VL - 136
SP - 177
EP - 192
JO - Monatshefte fur Chemie
JF - Monatshefte fur Chemie
IS - 2
ER -