Substrate-Controlled Synthesis of Functionalized Cyclohexanes with Four Stereocenters by Organocatalytic Asymmetric Domino Reactions Between -Nitro Ketone and Enone

摘要

Organocatalytic asymmetric domino reactions of -nitro ketones and enones have been developed for the construction of functionalized cyclohexane skeletons with four stereogenic carbon atoms, including one tetrasubstituted carbon stereocenter. 5-Nitropentan-2-one and 6-nitrohexan-3-one reacted with chalcone to afford six-membered carbocycles with four consecutive stereocenters in yields of 51-91% with 81-93% ee and >20:1 dr. In addition, 4-nitro-1-phenylbutan-1-one reacted with 4-arylbut-3-en-2-ones to afford six-membered carbocycles with two double consecutive stereocenters in yields of 59-92% with 89-94% ee and >20:1 dr. Interestingly, both four consecutive and nonconsecutive stereocenters could be constructed by these substrate-controlled domino reactions.