Diastereoselective Lewis acid-catalysed 4+2 cycloadditions of 3-alkyl-, 3-aryl- and 3-carboxyl-2H-azirines: a route to aziridine containing azabicyclo 4.1.0 heptanes and azatricyclo 22.214.171.124 nonanes
2002 (English)In: Tetrahedron, ISSN 0040-4020, E-ISSN 1464-5416, Vol. 58, no 30, 5983-5987 p.Article in journal (Refereed) Published
3-Substituted-2H-azirines have been employed as 2pi components in Lewis acid-catalysed hetero Diels-Alder reactions with a variety of diene systems. A series of Lewis acids were screened for catalytic behaviour in the reaction between Danishefsky's diene and 3-phenyl-2H-azirine to give the cycloaddition adduct, and in most cases elevated temperature were required to effect cycloaddition. A noteworthy exception was a BF3.Et2O-catalysed cycloaddition which proceeded in less than I h between -70degreesC and -60degreesC. The cycloadditions were found to proceed with endo selectivity providing a single diastereoisomeric product. Benzyl 2H-azirine-3-carboxylates were found to be activated by Lewis acids and participate in endo selective cycloadditions at -20degreesC.
Place, publisher, year, edition, pages
2002. Vol. 58, no 30, 5983-5987 p.
azirine, azifidine, hetero Diels-Alder reaction, diels-alder reactions, dienophiles, 2h-azirines
IdentifiersURN: urn:nbn:se:kth:diva-21752ISI: 000177028600003OAI: oai:DiVA.org:kth-21752DiVA: diva2:340450
QC 201005252010-08-102010-08-10Bibliographically approved