Aerobic Oxidation/Annulation Cascades through Synergistic Catalysis of RuCl3 and N-Heterocyclic Carbenes

作者：Wang, Qian; Chen, Jiean^*; Huang, Yong^*

来源：Chemistry - A European Journal, 2018, 24(49): 12806-12810.

DOI：10.1002/chem.201803254

• cooperative effects
• N-heterocyclic carbenes
• oxidation
• ruthenium
• synergistic catalysis

Cooperative catalysis combining a transition metal with an N-heterocyclic carbene is challenging due to strong binding of NHCs towards late transition metals. We report the first example of synergistic catalysis by a chiral NHC and a coordinatively unsaturated ruthenium compound. RuCl3 was found to mediate efficient aerobic oxidation of homoenolates generated from enals and the N-heterocyclic carbene. The resulting alpha,beta-unsaturated acylazolium intermediate reacts selectively with 1,3-dicarbonyl compounds or ketones at either the beta- or gamma-carbon, yielding polysubstituted chiral lactones in high yield and with excellent enantioselectivity (up to 98% yield, 94% ee). This protocol can be applied to structurally sophisticated substrates.

• 出版日期2018-9-3
• 单位北京大学深圳研究生院