Double cascade reactions based on the Barbas dienamine platform: highly stereoselective synthesis of functionalized cyclohexanes for cardiovascular agents
作者:Dhevalapally B. Ramachary、Y. Vijayendar Reddy、B. Veda Prakash
DOI:10.1039/b718122a
日期:——
amino acid proline catalyzed the three- and five-component cascade olefination-Diels-Alder-epimerization and olefination-Diels-Alder-epimerization-olefination-hydrogenation reactions of readily available precursors enones 1a-i, arylaldehydes 2a-k, alkyl cyanoacetates 3a-e and Hantzsch ester 9 to furnish highly substituted prochiral 1-cyano-4-oxo-2,6-diaryl-cyclohexanecarboxylic acid alkyl esters 6 and
Asymmetric Organocatalytic Double-Conjugate Addition of Malononitrile to Dienones: Efficient Synthesis of Optically Active Cyclohexanones
作者:Xue-ming Li、Bo Wang、Jun-min Zhang、Ming Yan
DOI:10.1021/ol102570b
日期:2011.2.4
9-Amino-9-deoxyepiquinine efficiently catalyzed the double-conjugate addition of malononitrile to dienones. A number of 1,1,2,6-tetrasubstituted cyclohexanones were prepared in good yields, diastereoselectivities, and excellent enantioselectivities.
Organocascade Reactions of Enones Catalyzed by a Chiral Primary Amine
addition sequence by chiral primary amine catalysis, which offers a powerful alternative in the design of synthetically useful organocascade reactions (see scheme, EWG=electron‐withdrawing group). This method complements the Diels–Alder reaction for the one‐step synthesis of complex cyclohexane scaffolds with excellent optical purity.