1,3-Dioxa-[3,3]-sigmatropic Oxo-Rearrangement of Substituted Allylic Carbamates: Scope and Mechanistic Studies

Maddalen Agirre (1) , S. Henrion (2) , Ivan Rivilla (1) , José Miranda (1) , Fernando Cossío (1, 3) , Bertrand Carboni (2) , José Villalgordo , François Carreaux (2)

1 UPV/EHU - Universidad del Pais Vasco / Euskal Herriko Unibertsitatea [Espagne]
2 ISCR - Institut des Sciences Chimiques de Rennes
3 Donostia International Physics Center

An unexpected 1,3-dioxa-[3,3]-sigmatropic rearrangement during the treatment of aryl-and alkenyl-substituted allylic alcohols with activated isocyanates is reported. The reorganization of bonds is highly dependent on the electron density of the aromatic ring and the nature of isocyanate used. This metal-free tandem reaction from branched allyl alcohols initiated by a carbamoylation reaction and followed by a sigmatropic rearrangement thus offers a new access to (E)-cinnamyl and conjugated (E,E)-diene carbamates, such as N-acyl and N-sulfonyl derivatives. A computational study was conducted in order to rationalize this phenomenon, and a rearrangement progress kinetic analysis was performed.

Domaines: Chimie organique

Maddalen Agirre, S. Henrion, Ivan Rivilla, José Miranda, Fernando Cossío, et al.. 1,3-Dioxa-[3,3]-sigmatropic Oxo-Rearrangement of Substituted Allylic Carbamates: Scope and Mechanistic Studies. Journal of Organic Chemistry, 2018, 83 (24), pp.14861-14881. ⟨10.1021/acs.joc.8b01320⟩. ⟨hal-01954300⟩