Enantioselective addition of diphenyl phosphonate to ketimines derived from isatins catalyzed by binaphthyl-modified organocatalysts

• Hee Seung Jang,
• Yubin Kim and
• Dae Young Kim

Beilstein J. Org. Chem. 2016, 12, 1551–1556, doi:10.3762/bjoc.12.149

• 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). Keywords: 3-amino-3-phosphonyl-substituted oxindole; α-aminophosphonates; bifunctional

• ][35]. Recently, there were a few reports on the synthesis of chiral 3-amino-3-phosphonyl-substituted oxindole derivatives by the catalytic enantioselective hydrophosphonation of ketimines [36][37]. The previous synthetic procedures suffered from several drawbacks, such as a high catalyst loading, long

• provided 3-amino-3-phosphonyl-substituted oxindole derivatives 3e and 3f in high yields (84% and 70%) with good enantioselectivities (99% ee and 88% ee, Table 2, entries 5 and 6). N-Benzylisatin imine 1g and 5-halogen-N-benzylisatin imines 1h–j reacted well with diphenyl phosphonate (2), giving 3-amino-3