(57) There is provided a method for producing a biarylalanine compound of formula (4):
wherein
R1 represents an amino protective group, and R2 represents an amino protective group or a hydrogen atom,
R3 is a carboxy protective group, or
said amino protective and carboxy protective groups together form an amino acid protective
group, and
R4 is a substituted or unsubstituted aryl or heteroaryl group, which comprises reacting
an aromatic amino acid of formula (1):
wherein
X is a halogen atom or a trifluoromethanesulfonyloxy group, and
R1, R2 and R3 are the same as defined above, with an organic boron compound of formula (2):
wherein R4 has the same meaning as defined above, and
Q1 and Q2 are the same or different and independently represent a hydroxy group or an alkoxy
group having 1 to 4 carbon atoms, or
Q1 and Q2 together form an alkylenedioxy or 1,2-phenylenedioxy group optionally substituted
by an alkyl group having 1 to 4 carbon atoms,
or
a boroxine ring compound of formula (3):
wherein R4 has the same meaning as defined above, or a mixture thereof, in the presence of a
nickel catalyst and a base.
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