Benzo[c][1,2]thiazine‐Based Analogs in the Inverse Electron Demand [4+2] Hetero Diels‐Alder Reaction with Glycals: Access to Tetracyclic Fused Galactose and Fucose Derivatives

Abstract

In memory of Prof. Giovanni Romeo, who gave a fundamental contribution to the field of cycloaddition reactionsThe synthesis and reactivity in an [4 + 2] inverse electron demand hetero Diels-Alder reaction (ihDA) of an original class of electronpoor heterodienes, the N-substituted-1H-benzo [c][1,2]thiazin-4one-2,2-dioxides, are described. These are highly reactive electrophiles that allow easy access to unprecedented benzo-thiazine glyco-fused derivatives in a remarkably selective way, even when using acetylated glycals, previously unexplored within this version of ihDA. DFT calculations support the experimental data, and moreover show that acetylated dienophiles can easily react making cycloadditions feasible.

Design of New Schiff Bases and Their Heavy Metal Ion Complexes for Environmental Applications: A Molecular Dynamics and Density Function Theory Study

“…Because of the high degree of conformational freedom of compounds 1-3 (Figure 1), to correctly describe their overall behavior and not neglect any possible conformations, the MD study was followed by a cluster analysis. Different conformational families, describing the structures, were located and the most representative ones, populated by more than 10%, were optimized using the widely exploited DFT methods [24][25][26][27].…”