title: Synthesis of conformationally restricted glutamate and glutamine derivatives from carbonylation of orthopalladated phenylglycine derivatives.
abstract: A new method for the regioselective synthesis of 2-alkoxycarbonyl- and 2-(aminocarbonyl)phenylglycinate methyl esters has been developed. The reaction of the orthopalladated complex [Pd(μ-Cl)(C(6)H(4)(CH(CO(2)Me)NMe(2))-2)](2) (1) with nucleophiles HNu under a CO atmosphere results in the selective incorporation of the C(O)Nu moiety to the phenyl ring and formation of the carbonyl species ortho-C(6)H(4)(C(O)Nu)(CH(CO(2)Me)NMe(2)) (2a-j) (Nu = OR, NHR, NR(2)). Compounds 2a-j are conformationally restricted analogues of glutamic acid and glutamine and are interesting due to their biological and pharmacological properties. The reaction of [Pd(μ-Cl)(C(6)H(4)(CH(CO(2)Me)NHTf)-2)](2) (3) with nucleophiles in a CO atmosphere results, however, in the formation of the cyclic isoindolinone or the open 2-carboxyphenylglycine methyl esters, with the reaction outcome being driven by the choice of the solvent.
authors.affiliation: Instituto de Síntesis Química y Catálisis Homogénea, CSIC - Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain.
authors.forename: Esteban P
authors.initials: EP
authors.lastname: Urriolabeitia
authors.forename: Eduardo
authors.initials: E
authors.lastname: Laga
authors.forename: Carlos
authors.initials: C
authors.lastname: Cativiela