Affiliation:
1. Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development Department of Chemistry East China Normal University 3663 North Zhongshan Road Shanghai 200062 China
2. Shanghai Frontiers Science Center of Molecule Intelligent Syntheses 3663 North Zhongshan Road Shanghai 200062, China China
Abstract
AbstractA copper‐catalyzed [3+2] annulation reaction of exocyclic enamines/enol ethers with 1,4‐benzoquinone esters has been developed, providing facile access to N,O‐spiroketals and spiroketals under mild conditions with broad substrate scope (26 examples, 71–94 % yields). Gram scale synthesis and chemical transformations demonstrated that this method is potentially useful in the synthesis of natural products and drugs containing a N,O‐ spiroketal moiety. The chiral N,O‐spiroketal could be obtained with 98 % ee after recrystallization, when a chiral SaBOX ligand was employed.