RESUMO
The efficient and atom economical synthesis of 5-membered cyclic structures has been achieved through the combination of amino catalysis and metal catalysis. The discovery of a novel metallo-organocatalytic system merging the use of a catalytic copper(I) complex and a catalytic amount of cyclohexylamine allowed the room temperature preparation of a broad range of skeletons such as cyclopentanes, indanes, pyrrolidines and tetrahydrofuran, important structural cores of many biologically relevant molecules. Mechanistic studies were presented.
RESUMO
An efficient and cheap synthetic approach to functionalized exo-methylene cyclopentanes has been developed from α-disubstituted formyl-alkynes by merging amine catalysis with the indium activation of alkynes. We uncovered the crucial role of the amine cocatalyst and the development of a new cooperative catalytic system allowed the cyclization of a broad range of substrates. A mechanistic study was realized in order to rationalize the determining influence of the amine cocatalyst.
RESUMO
Enantioselective metallo-organocatalyzed carbocyclizations of formyl-alkynes have been developed. The cooperation between aminocatalysis and a chiral copper(I) complex granted access to enantio-enriched cyclopentanes through the challenging formation of all-carbon quaternary stereocenters.
RESUMO
The combination of enamine-type catalysis to the indium-catalyzed activation of alkynes allows the efficient preparation of functionalized cyclopentanes bearing a quaternary stereogenic center. A broad range of formylalkynyl derivatives has been prepared. The InCl(3)/(Cy)(i-Pr)NH system efficiently promotes the carbocyclization reaction of alpha-disubstituted aldehydes in good to excellent yields.