Rhodium-Catalyzed Regio-, Diastereo-, and Enantioselective Intermolecular [4+2] Carbocyclization of 4-Alkynals with Electron-Deficient Alkenes
作者:Ken Tanaka、Yuji Hagiwara、Masao Hirano
DOI:10.1002/ejoc.200600383
日期:2006.8
We established that a cationic rhodium(I)/dppf or dppb complexcatalyzes a regio- and diastereoselective intermolecular [4+2] carbocyclization of 5-trimethylsilyl-4-pentynals with electron-deficient alkenes leading to cyclohexanones. We also established that a cationic rhodium(I)/(R,R)-Walphos complexcatalyzes a regio- and enantioselective intermolecular [4+2] carbocyclization of 5-substituted 4-pentynals
Synthesis of Chiral Tetrasubstituted Alkenes by an Asymmetric Cascade Reaction Catalyzed Cooperatively by Cationic Rhodium(I) and Silver(I) Complexes
作者:Daiki Hojo、Keiichi Noguchi、Ken Tanaka
DOI:10.1002/anie.200904024
日期:2009.10.12
have been prepared with high enantioselectivity by the title transformation. This reaction was successfully applied to the enantio‐ and diastereoselective synthesis of tetrasubstituted helical alkenes possessing both central and helical chirality (see scheme).
A cationic rhodium(I)/(R)-Segphos® [(4,4′-bi-1,3-benzodioxole)-5,5′-diylbis(diphenylphosphine)] complex catalyzes the highlyenantioselective [4 + 2] annulation of 2-alkynylbenzaldehydes with acyl ...
Rhodium-Catalyzed C–H Bond Activation/[4 + 2] Annulation/Aromatization Cascade To Produce Phenol, Naphthol, Phenanthrenol, and Triphenylenol Derivatives
作者:Daiki Hojo、Ken Tanaka
DOI:10.1021/ol300234g
日期:2012.3.16
It has been established that a cationic rhodium(I)/dppp complex catalyzes the aldehyde C–H bond activation/[4 + 2] annulation/aromatization cascade to produce phenol, naphthol, phenanthrenol, and triphenylenol derivatives from readily available conjugated alkynyl aldehydes and alkynes.