Enantioselective hydrophosphonylation of N - benzyl imines, isatin derived ketimines and isatins catalyzed by in-situ generated Ti(IV) macrocyclic salen complexes
作者:Mohd Nazish、Ajay Jakhar、Noor-ul H. Khan、Shailesh Verma、Rukhsana I. Kureshy、Sayed H.R. Abdi、Hari C. Bajaj
DOI:10.1016/j.apcata.2015.12.037
日期:2016.4
benzylimines, whereas for ketiminesdiphenylphosphite (IIb) gave best results with very good yield (up to 88%) and ee (up to 99%). The Ti(IV) complex was recoverable and recyclable with retention of its catalytic performance at gram scale level. To understand the reaction mechanism NMR studies have been carried out using benzylimine as a model substrate and dimethyl phosphite as a nucleophile.
First example of quinine-squaramide catalyzed enantioselective addition of diphenyl phosphite to ketimines derived from isatins
作者:Jimil George、B. Sridhar、B. V. Subba Reddy
DOI:10.1039/c3ob42026d
日期:——
A highlyenantioselective addition of diphenyl phosphite to ketimines derived from isatins has been achieved using a bifunctional organocatalyst, quinine-derived squaramide catalyst. This method works efficiently with several ketimines to produce the corresponding 3-amino-2-oxoindolin-3-yl-phosphonates in excellent yields with high enantioselectivity (up to 98% ee).
A highly enantioselective addition of diphenylphosphite to ketimines derived from isatins has been developed employing bifunctional thiourea-tertiary amine organocatalysts. A variety of isatins derived ketimines react well with diphenylphosphite in the presence of Cinchona-derived thiourea (epiCDT) to provide biologically important chiral 3-substituted 3-amino-2-oxindoles (3a–l) in good yield (up
Enantioselective addition of diphenyl phosphonate to ketimines derived from isatins catalyzed by binaphthyl-modified organocatalysts
作者:Hee Seung Jang、Yubin Kim、Dae Young Kim
DOI:10.3762/bjoc.12.149
日期:——
Chiral binaphthyl-modified squaramide-catalyzed enantioselectiveaddition of diphenyl phosphonate to ketimines derived from isatins has been achieved. This method affords practical and efficient access to chiral 3-amino-3-phosphonyl-substituted oxindole derivatives in high yields with excellent enantioselectivities (up to 99% ee).