Reactivity of cyclopalladated compounds derived from biphenyl-2-ylamine towards carbon monoxide, tbutyl isocyanide and alkynes

The reactivity of the dimeric cyclopalladated compounds derived from biphenyl-2-ylamine (mu-X)(2)[kappa(2)-N2',C1-1-Pd-2-{(2'-NH2C6H4) C6H4}](2) [X = OAc (1), X = Cl (2)] towards unsaturated organic molecules is reported. Compound 1 reacted with carbon monoxide and (t)butyl isocyanide producing phenanthridin-6(5H)-one and N-tert-butylphenanthridin-6-amine in 63% and 88% yield, respectively. Compound 2 reacted separately with diphenylacetylene and 3-hexyne, affording the mononuclear organopalladium compounds [kappa(2)-N-2",C1-eta(2)-C2,C3-1-Pd{(R-C = C-R)(2)-2'-(2"-NH2C6H4)c(6)H(4))Cl] [R = Ph (5), R = Et (6)] in 50-60% yield, which derived from the insertion of two alkyne molecules into the C-Pd sigma bonds of 2. The crystal structure of compounds 5 and 6 has been determined. Compound 5 crystallized in the monoclinic space group P2(1)/n with a = 13.3290(10) angstrom, b = 10.6610(10) angstrom and c = 22.3930(10) angstrom and beta = 100.2690(10)degrees. Compound 6 crystallized in the triclinic space group P (1) over bar with a = 7.271(7) angstrom, b = 10.038(3) angstrom and c = 16.012(5) angstrom, and alpha = 106.79(3)degrees, beta = 96.25(4)degrees and gamma = 99.62(4)degrees. The crystal structures of 5 and 6 have short intermolecular Pd-Cl center dot center dot center dot H-N-Pd non-conventional hydrogen bonds, which associated the molecules in chains in the first case and in dimers in the second. (C) 2007 Elsevier B.V. All rights reserved.