Metal Complexes of Biologically Important Ligands, CLV [1]. Some Derivatives of 4-Ethynylphenylalanine

Abstract

The benzoyl protected 4-ethynyl-L-phenylalanine methyl ester gives with octacarbonyldicobalt and ethylene-bis(triphenylphosphine)platinum(0) the complexes Co2(CO)6(HC≡CR) and (Ph3P)2 Pt(HC≡CR) (R = p-C6H4CH2CH(CO2Me)N(HCOPh). The heterocumulene [Cp(Ph3P)2Ru=C=C(H)R]+BF4− (R = p-C6H4CH2C(H)N(H)-Boc is formed from [Cp(Ph3P)2Ru]+BF4− and N-t-Boc-4-ethynylphenylalanine methyl ester. The alkynyl bridged tetraamino acid with a tetraphenylmethane backbone C[p-C6H4C≡C-p-C6H4-CH2CH(CO2Me)NH-t- Boc]4 was synthesized from tetrakis(4-iodophenyl)methane and N-Boc-4-ethynylphenylalanine methyl ester by Sonogashira coupling.