6-Substituted TpMo (CO) 2 (η-2, 3, 4-pyranyl)-and TpMo (CO) 2 (η-2, 3, 4-pyridinyl) scaffolds (Tp= hydridotrispyrazolylborato) function as reaction partners in an efficient regio-and stereocontrolled synthesis of functionalized oxa-and azabicyclo [3.2. 1] octenes through a novel Brønsted acid catalyzed [5+ 2] cycloaddition reaction. Excellent exo-selectivities are obtained, and the reaction gives products with complete retention of enantiomeric purity ...
