817577-63-2Relevant academic research and scientific papers
Comparative reactivity of Zr- and Pd-alkyl complexes with carbon dioxide
Lau, Ka-Cheong,Petro, Benjamin J.,Bontemps, Sebastien,Jordan, Richard F.
supporting information, p. 6895 - 6898 (2014/01/06)
Structure/reactivity trends and DFT studies reveal mechanistic differences and parallels for the carboxylation of Zr and Pd alkyls. CO2 reacts with Cp2ZrMe(C6D5Cl)+ >10 4 faster than with Cp2ZrMe2, yielding monoacetate products in both cases. These reactions proceed by insertion mechanisms in which Zr- - -O interactions activate the CO2. In contrast, CO2 reacts readily with [(PO-iPr)PdMe 2]- (PO-iPr- = 2-P iPr2-4-Me-C6H3SO3 -) to yield [(PO-iPr)PdMe(OAc)]- but not with (PO-iPr)PdMe(L) species. Carboxylation of [(PO-iPr) PdMe2]- occurs by direct SE2 attack of CO 2 at the Pd-Metrans-to-P group, and the nucleophilicity of the Pd-Me group controls the reactivity. However, the SE2 process is accelerated by a Li+- OCO interaction when Li+ is present.
Structures and reactivity of Zr(IV) chlorobenzene complexes
Wu, Fan,Dash, Aswini K.,Jordan, Richard F.
, p. 15360 - 15361 (2007/10/03)
The synthesis, structures, and unusual reactivity of (C5R5)2ZrR′(ClPh)+ chlorobenzene complexes are described. The reaction of (C5R5)2ZrR′2 with [Ph3C][B(C6F5)4] in C6D5Cl affords [(C5R5)2ZrR′(ClC6D5)][B(C6F5)4] chlorobenzene complexes (1-d5, R′ = CH2Ph and (C5R5)2 = (C5H5)5; 2a-d-d5, R′ = Me and (C5R5)2 = rac-(1,2-ethylene(bis)indenyl) (2a), (C5H5)5 (2b), (C5H4Me)2 (2c), (C5Me5)2 (2d, C5Me5 = Cp*)). Complexes 1 and 2b,c are thermally robust but are converted to [{(C5R5)5Zr(μ-Cl)}2][B(C6F5)4]2 (4b,c) by a photochemical process in ClPh solution. In contrast, 2d undergoes facile thermal ortho-C-H activation to yield [Cp*2Zr(η2-C,Cl-2-Cl-C6H5)][B(C6F5)4] (5), which slowly rearranges to [(η4,η1-C5Me5C6H4)Cp*ZrCl][B(C6F5)4] (6) via β-Cl elimination and benzyne insertion into a Zr-CCp* bond. The higher thermal reactivity of 2d versus that of 1 and 2b,c is attributed to steric crowding associated with the Cp* ligands of 2d, which forces a ClPh ortho-hydrogen close to the Zr-Me group. Copyright
