124536-94-3Relevant academic research and scientific papers
Molybdenum-mediated imido group transfer: Stoichiometric and catalytic reactions and structures
Harlan, Edgar W.,Holm
, p. 186 - 193 (2007/10/02)
The isoelectronic relationship O2 = RN2- implies imido group transfer chemistry related to oxygen atom transfer reactivity, which is extensive for certain elements. This has subjected to its first systematic examination, using the N,N-diethyldithiocarbamate (Ei2dtc) complexes of molybdenum and the N-tosylimido (NTs) group. The imido group transfer reactions to Mo, MoO(Et2dtc)2 + XNR and Mo(CO)2(Et2dtc)2 + XNR, afford MoO(NTs) (Et2dtc)2 and Mo(NTs)2(Et2dtc)2, respectively, in yield with the imido group transfer reagents XNR = C5H5NNTs, PhMeSNTs, Ph3SbNTs, PhINTs, nd TsN3, MoO(NTs) (Et2dtc)2·1/2Ph Me crystallizes crystallizes in triclinic space PI with a = 9.212 (2) A?, b = 12,080 (4) A?, c = 14.310 (4) A?, α = 115,02 (2)°, β = 95.51 (2)°, γ = 100.34 (2)°, and Z = 2; the structure was refined to R = 4.8%. Mo(NTs)2(Et2dtc)2 was obtained in monoclinic space group,P21/n with a = 10.632 (2) A?, b = 16.307 (3) A?, c = 19.023 (5) A?, β = 101.29 (2)°, Z = 4; the structure was refined to R = 4.0%. The two compounds have a distorted octahedral structure with the multiply bonded group O and NTs in cis positions. Comparison of structures with that of MoO2(Et2dtc)2 reveals that the NTs group is a nearly isostructural replacement for oxo. The imido transfer reactions from Mo, MoO(NTs)(Et2dtc)2 + R3P, proceed but with the more basic phosphines favoring imido (R3PNTs) rattier than oxo (R3PO) transfer. Imido transfer to and from Mo involve the purple intermediates Mo2O2(NTs)(Et2dtc)4 and MoO(NTs)2(Etjdtc)4, respectively, which are in presumed equilibrium with Mo(IV,VI) complexes. The complex Mo(NTs)(Et2dtc)2, resulting from imido group transfer, was too unstable to be isolated. Group transfers to and from Mo were coupled to form the catalytic XNTs + R3P → X + R3PNTs, which did not proceed at a measurable rate in the absence of Mo(NTs)2(Et2dtc)2. The system based on PhMeSNTs + Ph2MeP 28 turnovers in 7.5 h in chloroform at 35 °C. The PhMeSNTs + 2PMSH → PhSMe + PhSSPh + TsNH2, in which benzenethiot acts as an electron donor, was also catalyzed by Mo(NTs)2(Et2dtc)2. All known imidometal group are tabulated, and oxo and imido transfer reactions of Mo are schematically summarized. rized.
