A Highly Regio- and Stereoselective Cascade Annulation of Enals and Benzodi(enone)s Catalyzed by N-Heterocyclic Carbenes
作者:Xinqiang Fang、Kun Jiang、Chong Xing、Lin Hao、Yonggui Robin Chi
DOI:10.1002/anie.201007144
日期:2011.2.18
Three stereogenic centers in a row: The unconventional activation of enal compounds mediated by an N‐heterocyclic carbene (NHC) has generated three consecutive reactive carbon centers that undergo highly regio‐ and stereoselectiveannulations with di(enone)s to generate benzotricyclic products containing multiple stereogenic centers (see scheme).
skeletons has been explored. Under UV-light irradiation, o-divinylbenzenes underwent a pericyclic reaction to form the cyclic o-quinodimethane intermediates which were subsequently reacted with olefins through [4+2] addition to construct the benzobicyclo[2.2.2]octane skeletons in mild conditions. Gram scale reactions demonstrated the synthetic potential application of this protocol.
The photolysis of substituted o-divinylbenzenes promotes a one-step and metal-free conversion to oxatricycles at room temperature. Irradiation o-divinylbenzenes results in an pericyclic reaction to form cyclic o-quinodiemthane intermediates, which subsequently undergo intramolecular oxa-[4+2] cycloaddition to form oxacyclic derivatives.
Diastereoselective Synthesis of
1,2,3-Trisubstituted Indanes via Rhodium(I)-Catalyzed Tandem Conjugate
Additions
作者:Aurelio Csákÿ、Cristina Navarro
DOI:10.1055/s-0028-1083297
日期:——
1,2,3-Trisubstituted indanes are synthesized with high diastereoselectivity in favor of the all-trans products by the reaction of boronic acids with electron-deficient o-divinylbenzenes under rhodium(I) catalysis.
Stereoselective Borylcupration/Michael Addition on Symmetrical Dienones
作者:Laxman Devidas Khalse、Prasanta Ghorai
DOI:10.1021/acs.joc.2c02714
日期:2023.7.7
An efficient cascade protocol for the stereoselective synthesis of borylated carbocycles via copper-catalyzed borylative Michael/Michael cyclization is presented. Using this mild approach, up to 24 new boronic ester substituted indanes, cyclohexanes, and cyclopentanes were prepared in good yields with excellent diasteroselectivities and exceptional functional group tolerance. Furthermore, carbacyclic