Reference

Catalytic, asymmetric synthesis of 1,4-benzoxazinones: a remarkably enantioselective route to a-amino acid derivatives from o-benzoquinone imides

All Rights Reserved. Catalytic, asymmetric synthesis of 1,4-benzoxazinones: a remarkably enantioselective route to a-amino acid derivatives from o-benzoquinone imides. 1199-46-8 are also occured in this study. Wolfer, Jamison; Bekele, Tefsit; Abraham, Ciby J.; Dogo-Isonagie, Cejetan; Lectka, Thomas (Department of Chemistry, Johns Hopkins University, Baltimore, MD 21218, USA). Angewandte Chemie, International Edition, 45(44), 7398-7400 (English) 2006 Wiley-VCH Verlag GmbH & Co. KGaA. CODEN: ACIEF5. ISSN: 1433-7851. DOCUMENT TYPE: Journal CA Section: 34 (Amino Acids, Peptides, and Proteins) Section cross-reference(s): 28 Cycloaddn. of o-benzoquinone imides I (R1 = H, Cl; R2 = H, Cl, Me; R3 = Cl, F3C, Me3C; R4 = 4-O2NC6H4CO) with chiral ketene enolates, derived from acyl chlorides R5CH2COCl (R5 = F, Me, Et, Me2CHCH2, EtCYC, Ph, PhCH2, PhOCH2) in the presence of cinchona alkaloid catalysts, is the basis of a catalytic asym. synthesis of 1,4-benzoxazinones and 1,4-benzoxazines II (X = CH2, CO). The resulting cycloadducts can be derivatized in situ to provide a-amino acid esters and amides III (R6 = MeO, H2N, PhCH2NH) in good-to-excellent yields with very high enantioselectivities. Esters III (R6 = MeO) can be N-dearylated on treatment with CAN in aq. MeCN. .