Domino Reaction Of Heterocyclic Carbene And Organic Phosphonic Small Molecule Catalytic Research

The introduction of domino reaction as a concept into organic synthesis has inspired fruitful discoveries. They have great potential to meet several new criteria of an'ideal synthesis', namely atom, step, and redox economy.N-heterocyclic carbenes, as special and robust organocatalysts, have made an impressive contribution to the unprecedented domino reactions; and therefor opened a new pathway to the rapid formation of molecular complexity.Herein, a novel NHC-catalyzed three-component domino strategy to access highly functionalized acyclic cis-ε-ketoesters with excellent yields and high stereoselectivities is documented. This domino reaction is atom economical and works on a broad range of substrates. The relative stereochemistry could be explained by a cascade crossed-benzoin/oxy-Cope rearrangent/esterification process. The obtained product was further functinalized to a useful building block for organic synthesis.Phosphine organocatalysts have been subjected to intensive studies and have manifested their undeniable power in cyclization processes.We have developed unprecedented substrate-controlled and tripbutylphosphine-mediated domino reactions with high diastereoselectivities. A mechanism featuring the involvement of a ylide generated by intermolecular Rauhut-Currier (RC) reaction of activated conjugated diene was for the first time described. These domino reactions can provide bicyclic dihydrofuran derivatives with four contiguous stereogenic centers and bicyclic phosphoranes via a catalytic model and a catalytic-stoichiometric model, respectively.