Frija, L.Reva, I. D.Ismael, AminCoelho, DanielaFausto, R.Cristiano, Maria Lurdes Santos2014-06-072014-06-072011Frija, Luís M. T.; Reva, Igor; Ismael, Amin; Coelho, Daniela V.; Fausto, Rui; Cristiano, M. Lurdes S. Sigmatropic rearrangements in 5-allyloxytetrazoles, Organic & Biomolecular Chemistry, 9, 17, 6040-6054, 2011.1477-0520AUT: MCR00716http://hdl.handle.net/10400.1/4243Mechanisms of thermal isomerization of allyl tetrazolyl ethers derived from the carbocyclic allylic alcohols cyclohex-2-enol and 3-methylcyclohex-2-enol and from the natural terpene alcohol nerol were investigated. In the process of the syntheses of the three 1-aryl-5-allyloxytetrazoles, their rapid isomerization to the corresponding 1-aryl-4-allyltetrazol-5-ones occurred. The experiments showed that the imidates rearrange exclusively through a [3,3¢]-sigmatropic migration of the allylic system from O to N, with inversion. Mechanistic proposals are based on product analysis and extensive quantum chemical calculations at the DFT(B3LYP) and MP2 levels, on O-allyl and N-allyl isomers and on putative transition state structures for [1,3¢]- and [3,3¢]-sigmatropic migrations. The experimental observations could be only explained on the basis of the MP2/6-31G(d,p) calculations that favoured the [3,3¢]-sigmatropic migrations, yielding lower energies both for the transition states and for the final isomerization products.engjournal article2014-06-05http://dx.doi.org/10.1039/c1ob05460k