Intra- and Intermolecular 1,3-Dipolar Cycloaddition of Sugar Ketonitrones with Mono-, Di-, and Trisubstituted Dipolarophiles

The 1,3-dipolar cycloaddition of sugar ketonitrones is a useful synthetic procedure to build up
nitrogenated quaternary centers in terms of scope (substrate, dipolarophile, inter- and intramolecular versions), yield, and regio- and stereoselectivity. The hybrid ONIOM (B3LYP/6-31G(d):AM1) theoretical method followed by single-point energy calculations at the B3LYP/6-31G(d) level
adequately perform to model this cycloaddition for the relatively large ketosugar precursors
commonly used.

糖酮硝酮的1,3-偶极环加成（1,3-dipolar cycloaddition）是一种可构建含氮季碳中心的实用合成方法，其反应性能在底物范围、亲偶极体、分子间及分子内反应类型、产率以及区域选择性与立体选择性等维度均有出色表现。采用混合ONIOM (B3LYP/6-31G(d):AM1) 理论方法，并结合B3LYP/6-31G(d)水平下的单点能计算，可对当前常用的较大尺寸酮糖前体参与的该环加成反应实现精准建模。