Synthesis, Reactivity, and DFT Studies of Tantalum Complexes Incorporating Diamido-<i>N</i>-heterocyclic Carbene Ligands. Facile Endocyclic C−H Bond Activation
作者:Liam P. Spencer、Chad Beddie、Michael B. Hall、Michael D. Fryzuk
DOI:10.1021/ja063282x
日期:2006.9.1
elimination reactions with the diamine-NHC ligands, (Ar)[NCN]H(2) (where (Ar)[NCN]H(2) = (ArNHCH(2)CH(2))(2)(C(3)N(2)); Ar = Mes, p-Tol), provided complexes with a bidentate amide-amine donor configuration. Attempts to promote coordination of the remaining pendent amine donor were unsuccessful. Metathesis reactions with the dilithiated diamido-NHC ligand ((Ar)[NCN]Li(2)) and various Cl(x)Ta(NR'(2))(5-)(x)
Synthesis and Characterization of (Me<sub>3</sub>ECH<sub>2</sub>)<sub>2</sub>Ta(CHEMe<sub>3</sub>)Si(SiMe<sub>3</sub>)<sub>3</sub> (E = C, Si). Kinetic and Mechanistic Studies of the Formation of a Silyl Alkylidene Complex through Preferential Silane Elimination
作者:Liting Li、Jonathan B. Diminnie、Xiaozhan Liu、Jonathan L. Pollitte、Ziling Xue
DOI:10.1021/om960382a
日期:1996.8.6
respectively. The reaction of 9 with LiSi(SiMe3)3(THF)3 to form the silyl alkylidenecomplex 2 follows a pathway different from the reaction of (Me3ECH2)4TaCl (E = C, Si) with LiCH2EMe3 to form alkylalkylidenecomplexes (Me3ECH2)2TaCHEMe3. The decomposition of 9 was found to follow first-order kinetics, with ΔH⧧ = 17.2(1.0) kcal/mol and ΔS⧧ = −4(4) eu, and give an unstable dimeric alkylidenecomplex (Me3SiC
Synthesis of ethylenically unsaturated compounds from esters or amides
申请人:E. I. Du Pont de Nemours and Company
公开号:US04021429A1
公开(公告)日:1977-05-03
Certain hydrocarbylidene-niobium or -tantalum complexes react with esters or N,N-disubstituted amides to produce ethylenically unsaturated compounds. Exemplary is the reaction of trineopentyl(neopentylidene)tantalum with ethyl acetate to produce 2-ethoxy-4,4-dimethyl-2-pentene: ##STR1##
Hydrocarbylidene compounds of niobium and tantalum
申请人:E. I. Du Pont de Nemours and Company
公开号:US03988332A1
公开(公告)日:1976-10-26
Certain hydrocarbylidene compounds of niobium and tantalum react with oxo compounds to form olefins and are also useful as oxygen scavengers. The compounds can also be used to deposit tantalum or niobium mirrors by thermal decomposition. Exemplary is trineopentyl(neopentylidene)tantalum of the formula [(CH.sub.3).sub.3 CCH.sub.2 ].sub.3 Ta=CHC(CH.sub.3).sub.3.
Synthesis of ethylenically unsaturated compounds from aldehydes or
申请人:E. I. Du Pont de Nemours and Company
公开号:US03992472A1
公开(公告)日:1976-11-16
Certain hydrocarbylidene-niobium or -tantalum complexes react with aldehydes or ketones to produce ethylenically unsaturated compounds. Exemplary is the reaction of trineopentyl(neopentylidene)tantalum with acetone to produce 2,4,4-trimethyl-2-pentene: ##EQU1##