An Asymmetric, bifunctional catalytic approach to non-natural alpha-amino acid derivatives.
A catalytic, asymmetric process for the synthesis of 1,4-benzoxazinones from o-benzoquinone imides and ketene enolates is reported. Addition of Lewis acids (Zn(OTf)2, In(OTf)3, and in particular Sc(OTf)3) creates a bifunctional catalytic system that dramatically increases the reaction rate and the yield of these non-natural amino acid precursors while preserving the remarkable enantioselectivity inherent to the reaction. Cocatalyst Sc(OTf)3 increases the yield by up to 42% while producing products in >99% ee.
Paull
Daniel H
DH
Department of Chemistry, New Chemistry Building, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, USA.
Alden-Danforth
Ethan
E
Wolfer
Jamison
J
Dogo-Isonagie
Cajetan
C
Abraham
Ciby J
CJ
Lectka
Thomas
T
D000596:Amino Acids / Q000138:chemical synthesis / Q000737:chemistry*; D001688:Biological Products / Q000737:chemistry; D002384:Catalysis; D008670:Metals / Q000737:chemistry; D015394:Molecular Structure; D013237:Stereoisomerism
D000596:Amino Acids; D001688:Biological Products; D008670:Metals