126949-74-4

Upstream product

• 126949-60-8 Mo(N-2,6-Pr(i)2C₆H₃)2Cl₂ * dme 
• 7412-67-1 neopentyl lithium 
• 78923-65-6 N-trimethylsilyl-2,6-diisopropylaniline 
• 24544-04-5 2,6-diisopropylbenzenamine 
• 13132-23-5 2,2-dimethylpropylmagnesium chloride 

Relevant academic research and scientific papers

Well-Defined Silica Grafted Molybdenum Bis(imido) Catalysts for Imine Metathesis Reactions

Novel site-isolated tetracoordinated molybdenum complexes possessing bis(imido) ligands, [( - Si-O)2Mo( - NR)2] (R = t-Bu, 2,6-C6H3-i-Pr2), were immobilized on partially dehydroxylated silica (SiO2-200) by a rigorous surface organometallic chemistry protocol. The newly developed materials adorned with bis(imido) functional units, which were previously exploited mainly as spectator ligands on silica-supported olefin metathesis molybdenum catalysts, are found to be efficient heterogeneous catalytic systems for imine cross metathesis under mild conditions.

Bis((2,6-diisopropylphenyl)imido) complexes of molybdenum(VI)

The motybdenum(VI) complex (AR′N)2MoCl2· THF (Ar′ = 2,6-diisopropylphenyl) was prepared by reaction of MoO2Cl2 with Ar′NCO at 70°C in THF. The preparations of the derivatives Mo(NAr′)2Np2, Mo-(NAr′)2Mes2, Mo(NAr′)2MeSBr. Mo(NAr′)2(NEt2)Cl, and Mo-(NAr′)2(NEt2)2 from Mo(NAK)2Cl2-THF are described. In addition, the complex Mo(NAr′)2(NHAK)2 has been synthesized and characterized crystallographically. Crystal data: MoC48H70N4, Mr = 799.06, monoclinic, P21/n, a = 9.874 (3) A?, b = 24.004 (8) A?, c = 19.220 (7) A?, β = 93.34 (2) A?, V = 4547 A?3, Z = 4, ρcalc = 1.167 g cm-3, λ = 1.5418 A?, μ = 26.35 cm-1, T = -100°C, R = 4.22% for 4426 unique observed [I ≥ 3σ(I)] reflections, Rw = 7.65%.

Synthesis of molybdenum imido alkylidene complexes and some reactions involving acyclic olefins

The reaction between Mo(C-t-Bu)(dme)Cl3 (dme = 1,2-dimethoxyethane) and Me3SiNHAr (Ar = 2,6-diisopropylphenyl) yields Mo(C-t-Bu)(NHAr)Cl2(dme) (1), which upon treatment with a catalytic amount Of NEt3 is transformed into Mo(CH-t-Bu)(NAr)Cl2(dme) (2). Complexes of the type Mo(CH-t-Bu)(NAr)(OR)2 (OR = OCMe(CF3)2, OCMe2(CF3), O-t-Bu, or OAr) have been prepared from 2. Complexes of the type Mo(C-t-Bu)(NHAr)(OR)2 (OR = OCMe(CF3)2 or OAr) have been prepared from 1, but they cannot be transformed into Mo(CH-t-Bu)(NAr)(OR)2 complexes. A precursor to imido alkylidene complexes that is related to 2 has been prepared by the sequence MoO2 → MoO2Cl2 → Mo(NAr)2Cl2 → Mo-(NAr)2(CH2R′)2 → Mo(CHR′)(NAr)(OTf)2(dme) (R′ = t-Bu or CMe2Ph; OTf = OSO2CF3). Mo(CH-t-Bu)(NAr)(OTf)2(dme) crystallizes in the space group P1 with a = 17.543 ?, b = 19.008 ?, c = 9.711 ?, α = 91.91°, β = 99.30°, γ = 87.27°, Z = 4, Mr = 729.60, V = 3191.1 ?3, ρ(calcd) = 1.518 g cm-3. It is a pseudooctahedral species in which the imido and alkylidene ligands are cis to one another, the triflate ligands are mutually trans, and the tert-butyl group points toward the imido ligand (syn orientation). Neophylidene complexes, Mo(CHCMe2Ph)(NAr)(OR)2 (OR = O-t-Bu, OAr, or O-2-C6H4-t-Bu), have been prepared from Mo(CHCMe2Ph)(NAr)(triflate)2(dme). Activity for the metathesis of cis-2-pentene by Mo(CHR′)-(NAr)(OR)2 complexes roughly correlates with the electron-withdrawing ability of OR, being rapid when OR = OCMe(CF3)2 and slow to negligible when OR = O-t-Bu. In several cases it is clear from proton NMR studies that the alkylidene ligand can rotate on the NMR time scale; in Mo(CHSiMe3)(NAr)(OAr)2 it has been shown that ΔG?298 = 16.0 kcal mol-1 for this process. Mo[CH(SiMe3)CH(SiMe3)CH2](NAr)[OCMe 2(CF3)]2 has been observed and found to be ～3 orders of magnitude less stable than the analogous tungsten complex. Trigonal-bipyramidal Mo(CH2CH2CH2)(NAr)[OCMe(CF3) 2]2 can be prepared at 25 °C in high yield, but it decomposes over a period of 12 h. Instability of OCMe(CF3)2 metallacyclobutane complexes has been traced to reduction by β-hydride rearrangement to give an olefin. In one case a complex containing the olefin product, Mo(NAr)(Me3SiCH=CH2)[OCMe(CF3)2] 2, was isolated.