Combined InCl3- and Amine-Catalyzed Intramolecular Addition of α-Disubstituted Aldehydes onto Unactivated Alkynes
摘要:
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 InCl3/(Cy)(i-Pr)NH system efficiently promotes the carbocyclization reaction of alpha-disubstituted aldehydes in good to excellent yields.
Enantioselective metallo-organocatalyzed preparation of cyclopentanes bearing an all-carbon quaternary stereocenter
作者:Benjamin Montaignac、Chandrasekaran Praveen、Maxime R. Vitale、Véronique Michelet、Virginie Ratovelomanana-Vidal
DOI:10.1039/c2cc32823b
日期:——
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.
Copper(i)–amine metallo-organocatalyzed synthesis of carbo- and heterocyclic systems
作者:Benjamin Montaignac、Victor Östlund、Maxime R. Vitale、Virgnie Ratovelomanana-Vidal、Véronique Michelet
DOI:10.1039/c2ob06449a
日期:——
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
InCl<sub>3</sub>/CyNH<sub>2</sub> Cocatalyzed Carbocyclization Reaction: An Entry to α-Disubstituted <i>exo</i>-Methylene Cyclopentanes
作者:Benjamin Montaignac、Maxime R. Vitale、Virginie Ratovelomanana-Vidal、Véronique Michelet
DOI:10.1021/jo1018552
日期:2010.12.3
An efficient and cheap synthetic approach to functionalized exo-methylene cyclopentanes has been developed from alpha-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.