| 摘要 |
PROBLEM TO BE SOLVED: To obtain the subject derivative by reaction between a specific aromatic amino acid derivative and pinacolborane in the presence of a palladium catalyst and a trialkylamine to efficiently introduce an expensive boron 10 isotope thereinto. SOLUTION: This derivative is obtained by reaction between (A) an aromatic amino acid derivative of formula I (R1 is an amino-protective group; R2 is H or an amino-protective group; R3 is a 1-7C alkyl or 7-8C aralkyl; R2 and R3 are joined together to form methyl or carbonyl; X is iodine, bromine, chlorine or trifluoromethanesulfonyloxy) and (B) pinacolborane of formula II in the presence of (C) a palladium catalyst e.g. dichloro[1,1'-bias(diphenylphosphino) ferrocene]palladium (II)} at an equivalent or less amount, pref. 0.05-50 mol%, based on the substrate and (D) a trialkylamine (e.g. triethylamine) at an equivalent or more amount, pref. 1-5 equivalent, base on the substrate. |
