Palladium‐Catalyzed [4+2] and [6+2] Dipolar Cycloadditions for the Construction of Benzo[d]isothiazole 1,1‐Dioxide Fused 1,3‐Oxazinanes and 1,3‐Oxazocanes†

Abstract

Comprehensive SummaryThe Pd‐catalyzed dipolar cycloaddition represents a significant synthetic strategy for the construction of useful heterocyclic compounds. This study developed the dipolar [4+2] and [6+2] cycloaddition reactions of benzo[d]isothiazole 1,1‐dioxides (BDs) leading to the synthesis of BD‐fused 1,3‐oxazinane and 1,3‐oxazocane derivatives, respectively. In particular, the synthesis of BD‐fused 1,3‐oxazinanes demonstrated regio‐ and enantioselective characteristics, resulting in products with good yields, enantioselectivity and regioselectivity (if applicable). Furthermore, the [6+2] cycloaddition reaction developed in this work represented the first strategy for the synthesis of medium‐sized ring compounds based on BDs.