Buchwald-Hartwig C-N cross coupling reactions catalyzed by a pseudo-pincer Pd(II) compound

摘要

The reaction of the imino compound [C6H4-1-(OH)-3-(CH=NC6H2-2,4,6-Me-3)] (1)with [Pd(COD)Cl-2] affords in good yields the cyclometalated product [PdCl(H2NC6H2-2,4,6-Me-3){C6H3-2-(O-H)-6-(CH=NC6H2-2,4,6-Me-3)}](2), both species being unequivocally identified by single crystal X-ray structure analysis. Careful analysis of both structures in the solid state reveals the presence of important hydrogen bond interactions, leading in the case of the Pd(II)derivative to the formation of a pseudo-pinceron-covalent pincer compound [PdCl(H2NC6H2-2,4,6-Me-3){C6H3-2-(O-H)-6-(CH=NC6H2-2,4,6-Me-3)}] (2). The catalytic activity of this species was examined in Buchwald-Hartwig C-N cross coupling of morpholine with a series of p-substituted bromo-benzenes.