Small molecule activation by POC(sp3)OP-nickel complexes.

This contribution describes the reactivities of CO2 , CO, O2 , and ArNC with the pincer-type complexes [(κ(P) ,κ(C) ,κ(P') -POC sp 3OP)NiX] (POC sp 3OP=(R2 POCH2 )2 CH; R=iPr; X=OSiMe3 , NArH; Ar=2,6-iPr2 C6 H3 ). Reaction of the amido derivative with CO2 and CO leads to a simple insertion into the NiN bond to give stable carbamate and carbamoyl derivatives, respectively, the pincer ligand backbone remaining intact in both cases. In contrast, the analogous reactions with the siloxide derivative produced kinetically labile insertion products that either revert to the starting material (in the case of CO2 ) or react further to give the mixed-valent, dinickel species [(POC sp 3OP)Ni(II) {μ,κ(O) ,κ(P) ,κ(P') -OCOCH(CH2 CH2 OPR2 )2 }Ni(0) (CO)2 ].

On the stability of a POCsp3OP-type pincer ligand in nickel(II) complexes.

We describe the results of a study on the stabilities of pincer-type nickel complexes relevant to catalytic hydroalkoxylation and hydroamination of olefins, C-C and C-X couplings, and fluorination of alkyl halides. Complexes [(POCsp3 OP)NiX] are stable for X=OSiMe3 , OMes (Mes=1,3,5-Me3 C6 H2), NPh2, and CC-H, whereas the O(tBu) and N(SiMe3)2 derivatives decompose readily. The phenylacetylide derivative transforms gradually into the zero-valent species cis-[{κ(P),κ(C),κ(C')-(iPr2 POCH2 CHCH2 )}Ni{η(2),κ(C),κ(C')-(iPr2 P(O)CCPh)}].

2-{N-[(2,3,4,9-Tetra-hydro-1H-carbazol-3-yl)meth-yl]methyl-sulfonamido}-ethyl methane-sulfonate.

In the title compound, C17H24N2O5S2, the indole ring system is nearly planar [maximum deviation = 0.032 (1) Å] and the cyclo-hexene ring has a half-chair conformation. In the crystal, N-H⋯O hydrogen bonds link the mol-ecules into a chain running along the b-axis direction.

2-{4-Methyl-N-[(2,3,4,9-tetra-hydro-1H-carbazol-3-yl)meth-yl]benzene-sulfon-amido}-ethyl 4-methyl-benzene-sulfonate.

In the title compound, C29H32N2O5S2, the indole ring system is nearly planar, with a maximum deviation of 0.013 (2) Å, and the cyclo-hexenone ring has an envelope conformation with the methine C atom as the flap. The two methyl-benzene rings are approximately perpendicular to each other, making a dihedral angle of 89.