Gold(I)-Catalyzed Intramolecular [4+2] Cycloadditions of Arylalkynes or 1,3-Enynes with Alkenes: Scope and Mechanism
作者:Cristina Nieto-Oberhuber、Patricia Pérez-Galán、Elena Herrero-Gómez、Thorsten Lauterbach、Cristina Rodríguez、Salomé López、Christophe Bour、Antonio Rosellón、Diego J. Cárdenas、Antonio M. Echavarren
DOI:10.1021/ja075794x
日期:2008.1.1
The cyclizations of enynes substituted at the alkyne gives products of formal [4+2] cyclization with Au(I) catalysts. 1,8-Dien-3-ynes cyclize by a 5-exo-dig pathway to form hydrindanes. 1,6-Enynes with an aryl ring at the alkyne give 2,3,9,9a-tetrahydro-1H-cyclopenta[b]naphthalenes by a 5-exo-dig cyclization followed by a Friedel-Crafts-type ring expansion. A 6-endo-dig cyclization is also observed
Co/Rhheterobimetallic nanoparticles were prepared from cobalt-rhodium carbonyl clusters [Co2Rh2(CO)12 and Co3Rh(CO)12] and immobilized on charcoal. HR-TEM revealed that the size of the heterobimetallic nanoparticles was ca. 2 nm and ICP-AES analysis showed a 2 : 2 and a 3 : 1 cobalt-rhodium stoichiometry (Co2Rh2 and Co3Rh1) in the heterobimetallic nanoparticles. The Co/Rhheterobimetallic nanoparticles
Tandem Gold/Silver-Catalyzed Cycloaddition/Hydroarylation of 7-Aryl-1,6-enynes to Form 6,6-Diarylbicyclo[3.2.0]heptanes
作者:Bradley D. Robertson、Rachel E. M. Brooner、Ross A. Widenhoefer
DOI:10.1002/chem.201500371
日期:2015.4.7
[PCy2(o‐biphenyl)}AuCl] and AgSbF6 catalyze the tandemcycloaddition/hydroarylation of 7‐aryl‐1,6‐enynes with electron‐rich arenes to form 6,6‐diarylbicyclo[3.2.0]heptanes in good yield under mild conditions. Experimental observations point to a mechanism involving gold‐catalyzed cycloaddition followed by silver‐catalyzed hydroarylation of a bicyclo[3.2.0]hept‐1(7)‐ene intermediate.
Asymmetric Cobalt‐Catalyzed Regioselective Hydrosilylation/Cyclization of 1,6‐Enynes
作者:Yang'en You、Shaozhong Ge
DOI:10.1002/anie.202100775
日期:2021.5.17
>99 % ee. This cobalt‐catalyzed hydrosilylation/cyclization also occurred with prochiral secondary hydrosilane PhMeSiH2 to yield chiral alkylsilanes containing both carbon‐ and silicon‐stereogenic centers with excellent enantioselectivity, albeit with modest diastereoselectivity. The chiral organosilane products from this cobalt‐catalyzed asymmetrichydrosilylation/cyclization could be converted to
Cobalt-Catalyzed Asymmetric Hydroboration/Cyclization of 1,6-Enynes with Pinacolborane
作者:Songjie Yu、Caizhi Wu、Shaozhong Ge
DOI:10.1021/jacs.7b01708
日期:2017.5.17
We report a cobalt-catalyzed asymmetric hydroboration/cyclization of 1,6-enynes with catalysts generated from Co(acac)2 and chiral bisphosphine ligands and activated in situ by reaction with pinacolborane (HBpin). A variety of oxygen-, nitrogen-, and carbon-tethered 1,6-enynes underwent this asymmetric transformation, yielding both alkyl- and vinyl-substituted boronate esters containing chiral tetrahydrofuran