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1.
Werner Uhl Frank Hengesbach Jennifer Isermann Meisam Soleimani Lina Schürmann Alexander Hepp Marcus Layh 《无机化学与普通化学杂志》2019,645(20):1205-1214
Hydrogallation of Me3Si–C≡C–NR'2 with R2Ga–H (R = tBu, CH2tBu, iBu) yielded Ga/N‐based active Lewis pairs, R2Ga–C(SiMe3)=C(H)–NR'2 ( 7 ). The Ga and N atoms adopt cis‐positions at the C=C bonds and show weak Ga–N interactions. tBu2GaH and Me3Si–C≡C–N(C2H4)2NMe afforded under exposure of daylight the trifunctional digallium(II) compound [MeN(C2H4)2N](H)C=C(SiMe3)Ga(tBu)–Ga(tBu)C(SiMe3)=C(H)[N(C2H4)2NMe] ( 8 ), which results from elimination of isobutene and H2 and Ga–Ga bond formation. 8 was selectively obtained from the ynamine and [tBu(H)Ga–Ga(H)tBu]2[HGatBu2]2. 7a (R = tBu; NR'2 = 2,6‐Me2NC5H8) and H8C4N–C≡N afforded the adduct tBu2Ga‐C(SiMe3)=C(H)(2,6‐Me2NC5H8) · N≡C–NC4H8 ( 11 ) with the nitrile bound to gallium. The analogous ALP with harder Al atoms yielded an adduct of the nitrile dimer or oligomers of the nitrile at room temperature. The reaction of 7a with Ph–N=C=O led to the insertion of two NCO groups into the Ga–Cvinyl bond to yield a GaOCNCN heterocycle with Ga bound to O and N atoms ( 12 ). 相似文献
2.
1,4‐Di(isopropyl)‐1,4‐diazabutadiene as a Reagent for the Trapping of Monomeric Fragments of the Tetragalliumcluster Ga4[C(SiMe3)3]4 – Formation of an Unsaturated GaN2C2 Heterocycle and an Oxidation Product Containing a Ga‐O‐O‐Ga Group The tetrahedral tetragallium cluster Ga4[C(SiMe3)3]4 ( 1 ) dissociates upon dissolution to yield the monomeric fragments Ga‐R [R = C(SiMe3)3]. These monomers could be trapped now by the treatment of their solutions with 1,4‐di(isopropyl)‐1,4‐diazabutadiene. The product of the cycloaddition reaction ( 2 ) possesses a five‐membered GaN2C2 heterocycle with a coordinatively unsaturated gallium atom and an endocyclic C=C double bond. 2 is rather sensitive towards oxidation by traces of air. The contact with oxygen yielded a digallium peroxide [(C2N2iPr2)RGa‐O‐O‐GaR(C2N2iPr2)] ( 3 ) which was isolated in a very low yield only and which has a gallium atom attached to each oxygen atom of the inner peroxo group. Both chelating ligands of 3 possess an unpaired electron. 相似文献
3.
The reactions of PhCH2SiMe3 ( 1 ), PhCH2SiMe2tBu ( 2 ), PhCH2SiMe2Ph ( 3 ), 3,5‐Me2C6H3CH2SiMe3 ( 4 ), and 3,5‐Me2C6H3CH2SiMe2tBu ( 5 ) with nBuLi in tetramethylethylenediamine (tmeda) afford the corresponding lithium complexes [Li(tmeda)][CHRSiMe2R′] (R, R′ = Ph, Me ( 6 ), Ph, tBu ( 7 ), Ph, Ph ( 8 ), 3,5‐Me2C6H3, Me ( 9 ), and 3,5‐Me2C6H3, tBu ( 10 )), respectively. The new compounds 5 , 7 , 8 , 9 and 10 have been characterized by 1H and 13C NMR spectroscopy, compounds 7 , 8 and 9 also by X‐ray structure analysis. 相似文献
4.
tert‐Butyl(dichloromethyl)bis(trimethylsilyl)silane ( 4 ), prepared by the reaction of tert‐butylbis(trimethylsilyl)silane with trichloromethane and potassium tert‐butoxide, reacted with 2,4,6‐triisopropylphenyllithium (TipLi) (molar ratio 1 : 2) at room temperature to give (after hydrolytic workup) the silanol tBu(2,4,6‐iPr3C6H2)Si(OH)–CH(SiMe3)2 ( 15 ). The formation of 15 is discussed as proceeding through the indefinitely stable silene tBu(2,4,6‐iPr3C6H2)Si=C(SiMe3)2 ( 13 ), but attempts to isolate the compound failed. Treatment of (dibromomethyl)ditert‐butyl(trimethylsilyl)silane ( 7 ), made from tBu2(Me3Si)SiH, HCBr3 and KOtBu, with methyllithium (1 : 3) at –78 °C afforded tBu2MeSi–CHMeSiMe3 ( 19 ); 7 and phenyllithium (1 : 3) under similar conditions gave tBu2PhSi–CH2SiMe3 ( 20 ). The reaction paths leading to 15 , 19 and 20 are discussed. Reduction of 7 with lithium in THF produced the substituted ethylene tBu2(Me3Si)SiCH=CHSitBu2SiMe3 ( 21 ). For 21 the results of an X‐ray structural analysis are given. 相似文献
5.
Surprisingly Different Reaction Behavior of Alkali and Alkaline Earth Metal Bis(trimethylsilyl)amides toward Bulky N‐(2‐Pyridylethyl)‐N′‐(2,6‐diisopropylphenyl)pivalamidine
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Diana Kalden Ansgar Oberheide Dr. Claas Loh Dr. Helmar Görls Dr. Sven Krieck Prof. Dr. Matthias Westerhausen 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(31):10944-10959
N‐(2,6‐Diisopropylphenyl)‐N′‐(2‐pyridylethyl)pivalamidine (Dipp‐N=C(tBu)‐N(H)‐C2H4‐Py) ( 1 ), reacts with metalation reagents of lithium, magnesium, calcium, and strontium to give the corresponding pivalamidinates [(tmeda)Li{Dipp‐N=C(tBu)‐N‐C2H4‐Py}] ( 6 ), [Mg{Dipp‐N=C(tBu)‐N‐C2H4‐Py}2] ( 3 ), and heteroleptic [{(Me3Si)2N}Ae{Dipp‐N=C(tBu)‐N‐C2H4‐Py}], with Ae being Ca ( 2 a ) and Sr ( 2 b ). In contrast to this straightforward deprotonation of the amidine units, the reaction of 1 with the bis(trimethylsilyl)amides of sodium or potassium unexpectedly leads to a β‐metalation and an immediate deamidation reaction yielding [(thf)2Na{Dipp‐N=C(tBu)‐N(H)}] ( 4 a ) or [(thf)2K{Dipp‐N=C(tBu)‐N(H)}] ( 4 b ), respectively, as well as 2‐vinylpyridine in both cases. The lithium derivative shows a similar reaction behavior to the alkaline earth metal congeners, underlining the diagonal relationship in the periodic table. Protonation of 4 a or the metathesis reaction of 4 b with CaI2 in tetrahydrofuran yields N‐(2,6‐diisopropylphenyl)pivalamidine (Dipp‐N=C(tBu)‐NH2) ( 5 ), or [(thf)4Ca{Dipp‐N=C(tBu)‐N(H)}2] ( 7 ), respectively. The reaction of AN(SiMe3)2 (A=Na, K) with less bulky formamidine Dipp‐N=C(H)‐N(H)‐C2H4‐Py ( 8 ) leads to deprotonation of the amidine functionality, and [(thf)Na{Dipp‐N=C(H)‐N‐C2H4‐Py}]2 ( 9 a ) or [(thf)K{Dipp‐N=C(H)‐N‐C2H4‐Py}]2 ( 9 b ), respectively, are isolated as dinuclear complexes. From these experiments it is obvious, that β‐metalation/deamidation of N‐(2‐pyridylethyl)amidines requires bases with soft metal ions and also steric pressure. The isomeric forms of all compounds are verified by single‐crystal X‐ray structure analysis and are maintained in solution. 相似文献
6.
Investigations on the Reactivity of [Me2AlP(SiMe3)2]2 with Base‐stabilized Organogalliumhalides and ‐hydrides [Me2AlP(SiMe3)2]2 ( 1 ) reacts with dmap?Ga(Cl)Me2, dmap?Ga(Me)Cl2, dmap?GaCl3 and dmap?Ga(H)Me2 with Al‐P bond cleavage and subsequent formation of heterocyclic [Me2GaP(SiMe3)2]2 ( 2 ) as well as dmap?AlMexCl3?x (x = 3 8 ; 2 3 ; 1 4 ; 0 5 ). The reaction between equimolar amounts of dmap?Al(Me2)P(SiMe3)2 and dmap?Ga(t‐Bu2)Cl yield dmap?Ga(t‐Bu2)P(SiMe3)2 ( 6 ) and dmap?AlMe2Cl ( 3 ). 2 – 8 were characterized by NMR spectroscopy, 2 and 6 also by single crystal X‐ray diffraction. 相似文献
7.
Verena M. Birkelbach Dr. Renita Thim Dr. Christoph Stuhl Dr. Cäcilia Maichle-Mössmer Prof. Dr. Reiner Anwander 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(64):14711-14720
A series of solvent-free heteroleptic terminal rare-earth-metal alkyl complexes stabilized by a superbulky tris(pyrazolyl)borato ligand with the general formula [TptBu,MeLnMeR] have been synthesized and fully characterized. Treatment of the heterobimetallic mixed methyl/tetramethylaluminate compounds [TptBu,MeLnMe(AlMe4)] (Ln=Y, Lu) with two equivalents of the mild halogenido transfer reagents SiMe3X (X=Cl, I) gave [TptBu,MeLnX2] in high yields. The addition of only one equivalent of SiMe3Cl to [TptBu,MeLuMe(AlMe4)] selectively afforded the desired mixed methyl/chloride complex [TptBu,MeLuMeCl]. Further reactivity studies of [TptBu,MeLuMeCl] with LiR or KR (R=CH2Ph, CH2SiMe3) through salt metathesis led to the monomeric mixed-alkyl derivatives [TptBu,MeLuMe(CH2SiMe3)] and [TptBu,MeLuMe(CH2Ph)], respectively, in good yields. The SiMe4 elimination protocols were also applicable when using SiMe3X featuring more weakly coordinating moieties (here X=OTf, NTf2). X-ray structure analyses of this diverse set of new [TptBu,MeLnMeR/X] compounds were performed to reveal any electronic and steric effects of the varying monoanionic ligands R and X, including exact cone-angle calculations of the tridentate tris(pyrazolyl)borato ligand. Deeper insights into the reactivity of these potential precursors for terminal alkylidene rare-earth-metal complexes were gained through NMR spectroscopic studies. 相似文献
8.
Roxana M. Bîrzoi Dr. Delia Bugnariu Dr. Rafael Guerrero Gimeno Dr. Daniela Lungu Vera Zota Dr. Constantin Daniliuc Dr. Peter G. Jones Prof. Dr. Zoltán Benkõ Dr. László Könczöl László Nyulászi Prof. Dr. Rainer Bartsch Dr. Wolf‐W. du Mont Prof. Dr. Edgar Niecke Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(16):4843-4851
Deprotonation of aminophosphaalkenes (RMe2Si)2C?PN(H)(R′) (R=Me, iPr; R′=tBu, 1‐adamantyl (1‐Ada), 2,4,6‐tBu3C6H2 (Mes*)) followed by reactions of the corresponding Li salts Li[(RMe2Si)2C?P(M)(R′)] with one equivalent of the corresponding P‐chlorophosphaalkenes (RMe2Si)2C?PCl provides bisphosphaalkenes (2,4‐diphospha‐3‐azapentadienes) [(RMe2Si)2C?P]2NR′. The thermally unstable tert‐butyliminobisphosphaalkene [(Me3Si)2C?P]2NtBu ( 4 a ) undergoes isomerisation reactions by Me3Si‐group migration that lead to mixtures of four‐membered heterocyles, but in the presence of an excess amount of (Me3Si)2C?PCl, 4 a furnishes an azatriphosphabicyclohexene C3(SiMe3)5P3NtBu ( 5 ) that gave red single crystals. Compound 5 contains a diphosphirane ring condensed with an azatriphospholene system that exhibits an endocylic P?C double bond and an exocyclic ylidic P(+)? C(?)(SiMe3)2 unit. Using the bulkier iPrMe2Si substituents at three‐coordinated carbon leads to slightly enhanced thermal stability of 2,4‐diphospha‐3‐azapentadienes [(iPrMe2Si)2C?P]2NR′ (R′=tBu: 4 b ; R′=1‐Ada: 8 ). According to a low‐temperature crystal‐structure determination, 8 adopts a non‐planar structure with two distinctly differently oriented P?C sites, but 31P NMR spectra in solution exhibit singlet signals. 31P NMR spectra also reveal that bulky Mes* groups (Mes*=2,4,6‐tBu3C6H2) at the central imino function lead to mixtures of symmetric and unsymmetric rotamers, thus implying hindered rotation around the P? N bonds in persistent compounds [(RMe2Si)2C?P]2NMes* ( 11 a , 11 b ). DFT calculations for the parent molecule [(H3Si)2C?P]2NCH3 suggest that the non‐planar distortion of compound 8 will have steric grounds. 相似文献
9.
Peter Paetzold Claudia Stanescu Jrg Rainer Stubenrauch Matthias Bienmüller Ulli Englert 《无机化学与普通化学杂志》2004,630(15):2632-2640
The 1‐azonia‐2‐boratanaphthalenes (NH)(BX)C8H6 can be synthesized from 2‐aminostyrene and the dihaloboranes XBHal2 ( 1 ‐ 4 : X = Cl, Br, iPr, tBu). Further derivatives (NH)(BX)C8H6 are obtained from 1 by replacing Cl by alkoxy or alkyl groups [ 5 ‐ 8 : X = OMe, OtBu, Me, (CH2)3NMe2]. The hydrolysis of 1 gives a mixture of the bis(azoniaboratanaphthyl) oxide [(NH)BC8H6]2O ( 9 ) and the hydroxy derivative (NH)[B(OH)]C8H6 ( 10 ). The diboryl oxide 9 crystallizes in the space group C2/c. The lithiation of 4 at the nitrogen atom gives [NLi(tmen)](BtBu)C8H6 ( 11 ), which upon reaction with the diborane(4) B2Cl2(NMe2)2 yields the 1, 2‐bis(azoniaboratanaphthyl)diborane B2[N(BtBu)C8H6]2(NMe2)2 ( 12 ). The 2‐chloro‐1‐methyl‐4‐phenyl derivative (NMe)(BCl)C8H5Ph ( 13 ) of the parent (NH)(BH)C8H6 can be synthesized from the aminoborane BCl2(NMePh) and phenylethyne. Substitution of Cl in 13 gives the derivatives (NMe)(BX)C8H5Ph [ 14 ‐ 20 : X = N(SiMe3)2, Me, Et, iBu, tBu, CH2SiMe3, Ph] and the reaction of 13 with Li2O affords the bis(azoniaboratanaphthyl) oxide [(NMe)BC8H5Ph]2O ( 21 ). The reaction of 16 or 19 with [(MeCN)3Cr(CO)3] yields the complexes [{(NMe)(BX)C8H5Ph}Cr(CO)3] ( 22 , 23 : X = Et, CH2SiMe3), in which the chromium atom is hexahapto bound to the homoarene part of 16 or 19 , respectively. The complex 23 crystallizes in the space group P21/c. Upon reaction of the phenols para‐C6H4R(OH) with the aryldichloroboranes ArBCl2 and subsequent condensation of the products with phenylethyne, the 1‐oxonia‐2‐boratanaphthalenes O(BAr)C8H4RPh with R in position 6 and Ph in position 4 are formed ( 24 ‐ 26 : Ar = Ph, R = H, Me, OMe; 27 ‐ 29 : Ar = C6F5, R = H, Me, OMe). The azoniaboratanaphthalenes 1 ‐ 23 were characterized by NMR methods. 相似文献
10.
Bisaminophosphanes – Synthesis, Structure, and Reactivity Different pathways for the synthesis of bis(alkylamino)phosphanes RP(N(H)R′)2 are described. t‐BuP(N(H)‐ Dipp)2 (Dipp = 2,6‐i‐Pr2–C6H3) was structurally characterized by single crystal X‐ray diffraction. The reactivity of the compounds was examplarily investigated using t‐BuP(N(H)t‐Bu)2. Its reaction with Me3Al and R2AlH (R = Me, Et, i‐Bu) in 1 : 1 and 1 : 2 stoichiometrie yield monosubstituted compounds of the type t‐BuP(N(H)t‐Bu)(N(AlR2)t‐Bu). 相似文献
11.
Matthias Westerhausen Christin Birg Mathias Krofta Peter Mayer Thomas Seifert Heinrich Nth Arno Pfitzner Tom Nilges Hans‐Jrg Deiseroth 《无机化学与普通化学杂志》2000,626(5):1073-1080
Synthesis and Structures of Sr6P8 Polyhedra in Mixed Phosphanides/Phosphandiides of Strontium The strontiation of H2PSiiPr3 ( 1 ) with (THF)2Sr[N(SiMe3)2]2 in THF yields colorless tetrakis(tetrahydrofuran‐O)strontium bis(triisopropylsilylphosphanide) ( 3 ). The central alkaline earth metal atom has an octahedral environment with the phosphanide ligands in trans position. The homometalation in toluene leads to the elimination of 1 and THF. Cooling of this solution gives crystals of colorless tetrakis(tetrahydrofuran‐O)hexastrontium‐tetrakis(triisopropylsilylphosphanide)‐tetrakis(triisopropylsilylphosphandiide) ( 4 ). The equimolar reaction of H2PSitBu3 ( 2 ) with (THF)2Sr[N(SiMe3)2]2 in toluene yields in the first step heteroleptic dimeric {(Me3Si)2NSr(THF)2[P(H)SitBu3]}2 ( 5 )2. This compounds monomerizes in THF to (Me3Si)2N–Sr(THF)4[P(H)SitBu3] ( 6 ), which forms an equilibrium with the homoleptic dismutation products (THF)2Sr[N(SiMe3)2]2 and (THF)4Sr[P(H)SitBu3]2 ( 7 ). Compound ( 5 )2 undergoes a intramolecular strontiation and bis(tetrahydrofuran‐O)hexastrontium‐tetrakis[tri(tert‐butyl)silylphosphanide]‐tetrakis[tri(tert‐butyl)silylphosphandiide] ( 8 ) is isolated. The central Sr6P8‐polyhedra of 4 and 8 are very similar. 相似文献
12.
Structural Characterization of Bis(metallated) Derivatives of 3, 3‐Dimethyl‐1, 5‐bis(trimethylsilyl)‐1, 5‐diaza‐pentane with Lithium and Aluminum and of two Donor‐substituted Digallanes The diaminopropane derivative Me2C[CH2N(H)SiMe3]2 is metallated with n‐butyllithium and lithium tetrahydridoaluminate to obtain Me2C[CH2N(Li)SiMe3]2 and Me2C[CH2N(Li)SiMe3][CH2N(AlH2)SiMe3], respectively. Both compounds exhibit a central eight‐membered ring, Li4N4 or Li2Al2N4. Me2C[CH2N(Li)SiMe3]2 reacts with Ga2Cl4 · 2dioxane under formation of the corresponding tetra(amino)digallane. This is monomeric, in contrast to a dimeric tetraalkoxy‐substituted digallane, Ga4OtBu8. All compounds were characterized by single crystal X‐ray crystallography. 相似文献
13.
Diimido, Imido Oxo, Dioxo, and Imido Alkylidene Halfsandwich Compounds via Selective Hydrolysis and α—H Abstraction in Molybdenum(VI) and Tungsten(VI) Organyl Complexes Organometal imides [(η5‐C5R5)M(NR′)2Ph] (M = Mo, W, R = H, Me, R′ = Mes, tBu) 4 — 8 can be prepared by reaction of halfsandwich complexes [(η5‐C5R5)M(NR′)2Cl] with phenyl lithium in good yields. Starting from phenyl complexes 4 — 8 as well as from previously described methyl compounds [(η5‐C5Me5)M(NtBu)2Me] (M = Mo, W), reactions with aqueous HCl lead to imido(oxo) methyl and phenyl complexes [(η5‐C5Me5)M(NtBu)(O)(R)] M = Mo, R = Me ( 9 ), Ph ( 10 ); M = W, R = Ph ( 11 ) and dioxo complexes [(η5‐C5Me5)M(O)2(CH3)] M = Mo ( 12 ), M = W ( 13 ). Hydrolysis of organometal imides with conservation of M‐C σ and π bonds is in fact an attractive synthetic alternative for the synthesis of organometal oxides with respect to known strategies based on the oxidative decarbonylation of low valent alkyl CO and NO complexes. In a similar manner, protolysis of [(η5‐C5H5)W(NtBu)2(CH3)] and [(η5‐C5Me5)Mo(NtBu)2(CH3)] by HCl gas leads to [(η5‐C5H5)W(NtBu)Cl2(CH3)] 14 und [(η5‐C5Me5)Mo(NtBu)Cl2(CH3)] 15 with conservation of the M‐C bonds. The inert character of the relatively non‐polar M‐C σ bonds with respect to protolysis offers a strategy for the synthesis of methyl chloro complexes not accessible by partial methylation of [(η5‐C5R5)M(NR′)Cl3] with MeLi. As pure substances only trimethyl compounds [(η5‐C5R5)M(NtBu)(CH3)3] 16 ‐ 18 , M = Mo, W, R = H, Me, are isolated. Imido(benzylidene) complexes [(η5‐C5Me5)M(NtBu)(CHPh)(CH2Ph)] M = Mo ( 19 ), W ( 20 ) are generated by alkylation of [(η5‐C5Me5)M(NtBu)Cl3] with PhCH2MgCl via α‐H abstraction. Based on nmr data a trend of decreasing donor capability of the ligands [NtBu]2— > [O]2— > [CHR]2— ? 2 [CH3]— > 2 [Cl]— emerges. 相似文献
14.
Chiral (1,2)‐Diphenylethylene‐Salen Complexes of Triel Metals: Coordination Patterns and Mechanistic Considerations in the Isoselective ROP of Lactide
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Nicolas Maudoux Dr. Thierry Roisnel Dr. Vincent Dorcet Prof. Dr. Jean‐François Carpentier Dr. Yann Sarazin 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(20):6131-6147
The synthesis of enantiomerically pure aluminium, gallium and indium complexes supported by chiral (R,R)‐(HHONNOHH) ( 1 ), (R,R)‐(MeHONNOHMe) ( 2 ), (R,R)‐(tButBuONNOtButBu) ( 3 ), (R,R)‐(MeNO2ONNOMeNO2) ( 4 ), (R,R)‐(HOMeONNOHOMe) ( 5 ) and (R,R)‐(ClClONNOClCl) ( 6 ) (1,2)‐diphenylethylene‐salen ligands is described. Several of these complexes have been crystallographically authenticated, which highlights a diversity of coordination patterns. Whereas all Ga complexes form [Ga2(CH2SiMe3)4(ONNO)] bimetallic species (ONNO= 1 – 3 ), aluminium [AlR(ONNO)] (R=Me, CH2SiMe3) and indium [In(CH2SiMe3)(ONNO)] derivatives are monometallic for ONNO= 1 , 2 and 4 – 6 , and only form the bimetallic complexes [Al2R4(ONNO)] and [In2(CH2SiMe3)4(ONNO)] for the most sterically crowded ligand 3 . The [AlMe(ONNO)] complexes react with iPrOH to give [AlOiPr(ONNO)] complexes that are robust towards further iPrOH. The [In(CH2SiMe3)(ONNO)] congeners are inert towards excess alcohol, whereas the Ga compounds decompose easily. All these alkyl complexes, as well as the [AlOiPr(ONNO)] derivatives, catalyse the ring‐opening polymerisation (ROP) of racemic lactide (rac‐LA). The [AlMe(ONNO)] complexes require additional alcohol to afford controlled reactions, but [AlOiPr(ONNO)] complexes are single‐component catalysts for the isoselective ROP of rac‐LA, with values of Pm in the range 0.80–0.90. Experimental evidence unexpectedly shows that chain‐end control leads to the isoselectivity of these aluminium catalysts; also, the more crowded the coordination sphere, the higher the isoselectivity. The bimetallic Ga complexes do not afford controlled reactions, but the binary [In(ONNO)(CH2SiMe3)/(PhCH2OH)] systems competently mediate non‐stereoselective ROP; evidence is given that an activated monomer mechanism is at work. Kinetic studies show that catalytic activity decreases when electronic density and steric congestion at the metal atom increase. 相似文献
15.
Ewald Sattler Harald Krautscheid Eberhard Matern Gerhard Fritz Ilona Kovcs 《无机化学与普通化学杂志》2001,627(2):186-193
Formation and Reactions of the CH2Li‐Derivatives of tBu2P–P=P(CH3)tBu2 and (Me3Si)tBuP–P=P(CH3)tBu2 With nBuLi, (Me3Si)tBuP–P=P(CH3)tBu2 ( 1 ) and tBu2P–P=P(CH3)tBu2 ( 2 ) yield (Me3Si)tBuP–P=P(CH2Li)tBu2 ( 3 ) and tBu2P–P=P(CH2Li)tBu2 ( 4 ), wich react with Me3SiCl to give (Me3Si)tBuP–P=P(CH2–SiMe3)tBu2 ( 5 ) and tBu2P–P=P(CH2–SiMe3)tBu2 ( 6 ), respectively. With tBu2P–P(SiMe3)–PtBuCl ( 7 ), compound 3 forms 5 as well as the cyclic products [H2C–P(tBu)2=P–P(tBu)–PtBu] ( 8 ) and [H2C–P(tBu)2=P–P(PtBu2)–P(tBu)] ( 9 ). Also 3 forms 8 with tBuPCl2. The cleavage of the Me3Si–P‐bond in 1 by means of C2Cl6 or N‐bromo‐succinimide yields (Cl)tBuP–P=P(CH3)tBu2 ( 10 ) or (Br)tBuP–P=P(CH3)tBu2 ( 11 ), resp. With LiP(SiMe3)2, 10 forms (Me3Si)2P–P(tBu)–P=P(CH3)tBu2 ( 12 ), and Et2P–P(tBu)–P=P(CH3)tBu2 ( 13 ) with LiPEt2. All compounds are characterized by 31P NMR Data and mass spectra; the ylide 5 and the THF adduct of 4 additionally by X‐ray structure analyses. 相似文献
16.
17.
Dr. Shihui Li Dr. Meiyan Wang Bo Liu Lei Li Prof. Jianhua Cheng Dr. Chunji Wu Dr. Dongtao Liu Prof. Dr. Jingyao Liu Prof. Dr. Dongmei Cui 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(47):15493-15498
The first four‐coordinate methanediide/alkyl lutetium complex (BODDI)Lu2(CH2SiMe3)2(μ2‐CHSiMe3)(THF)2 (BODDI=ArNC(Me)CHCOCHC(Me)NAr, Ar=2,6‐iPr2C6H3) ( 1 ) was synthesized by a thermolysis methodology through α‐H abstraction from a Lu–CH2SiMe3 group. Complex 1 reacted with equimolar 2,6‐iPrC6H3NH2 and Ph2C?O to give the corresponding lutetium bridging imido and oxo complexes (BODDI)Lu2(CH2SiMe3)2(μ2‐N‐2,6‐iPr2C6H3)(THF)2 ( 2 ) and (BODDI)Lu2(CH2SiMe3)2(μ2‐O)(THF)2 ( 3 ). Treatment of 3 with Ph2C?O (4 equiv) caused a rare insertion of Lu–μ2‐O bond into the C?O group to afford a diphenylmethyl diolate complex 4 . Reaction of 1 with PhN=C?O (2 equiv) led to the migration of SiMe3 to the amido nitrogen atom to give complex (BODDI)Lu2(CH2SiMe3)2‐μ‐{PhNC(O)CHC(O)NPh(SiMe3)‐κ3N,O,O}(THF) ( 5 ). Reaction of 1 with tBuN?C formed an unprecedented product (BODDI)Lu2(CH2SiMe3){μ2‐[η2:η2‐tBuNC(=CH2)SiMe2CHC?NtBu‐κ1N]}(tBuN?C)2 ( 6 ) through a cascade reaction of N?C bond insertion, sequential cyclometalative γ‐(sp3)‐H activation, C?C bond formation, and rearrangement of the newly formed carbene intermediate. The possible mechanistic pathways between 1 , PhN?C?O, and tBuN?C were elucidated by DFT calculations. 相似文献
18.
Phosphine (oxide)‐(thio) phenolate palladium complexes: Synthesis,characterization and (co)polymerization of norbornene
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A series of palladium complexes ( 2a–2g ) ( 2a : [6‐tBu‐2‐PPh2‐C6H3O]PdMe(Py); 2b : [6‐C6F5–2‐PPh2‐C6H3O]PdMe(Py); 2c : [6‐tBu‐2‐PPhtBu‐C6H3O]PdMe(Py); 2d : [2‐PPhtBu‐C6H4O] PdMe(Py); 2e : [6‐SiMe3–2‐PPh2‐C6H3O]PdMe(Py); 2f : [2‐tBu‐6‐(Ph2P=O)‐C6H3O]PdMe(Py); 2g : [6‐SiMe3–2‐(Ph2P=O)‐C6H3S]PdMe(Py)) bearing phosphine (oxide)‐(thio) phenolate ligand have been efficiently synthesized and characterized. The solid‐state structures of complexes 2d , 2f and 2g have been further confirmed by single‐crystal X‐ray diffraction, which revealed a square‐planar geometry of palladium center. In the presence of B(C6F5)3, these complexes can be used as catalysts to polymerize norbornene (NB) with relatively high yields, producing vinyl‐addition polymers. Interestingly, 2a /B(C6F5)3 system catalyzed the polymerization of NB in living polymerization manner at high temperature (polydispersity index 1.07, Mn up to 1.5 × 104). The co‐polymerization of NB and polar monomers was also studied using catalysts 2a and 2f . All the obtained co‐polymers could dissolve in common solvent. 相似文献
19.
Theoretical Study of Pd11Si6 Nanosheet Compounds Including Seven‐Coordinated Si Species and Its Ge Analogues
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Dr. Yue Chen Yusuke Sunada Prof. Dr. Hideo Nagashima Prof. Dr. Shigeyoshi Sakaki 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(3):1076-1087
Nanosheet compounds Pd11(SiiPr)2(SiiPr2)4(CNtBu)10 ( 1 ) and Pd11(SiiPr)2(SiiPr2)4(CNMes)10 ( 2 ), containing two Pd7(SiiPr)(SiiPr2)2(CNR)4 plates (R=tBu or Mes) connected with three common Pd atoms, were investigated with DFT method. All Pd atoms are somewhat positively charged and the electron density is accumulated between the Pd and Si atoms, indicating that a charge transfer (CT) occurs from the Pd to the Si atoms of the SiMe2 and SiMe groups. Negative regions of the Laplacian of the electron density were found between the Pd and Si atoms. A model of a seven‐coordinated Si species, that is, Pd5(Pd?SiMe), is predicted to be a stable pentagonal bipyramidal molecule. Five Pd atoms in the equatorial plane form bonding overlaps with two 3p orbitals of the Si atom. This is a new type of hypervalency. The Ge analogues have geometry and an electronic structure similar to those of the Si compounds. But their formation energies are smaller than those of the Si analogues. The use of the element Si is crucial to synthesize these nanoplate compounds. 相似文献
20.
Amination of the C‐isopropyldimethylsilyl P‐chlorophosphaalkene (iPrMe2Si)2C=PCl ( 1 ) leads to the P‐aminophosphaalkenes (iPrMe2Si)2C=PN(R)R′ (R, R′ = Me ( 2 ), R = H, R′ = nPr ( 3 ), R = H, R′ = iPr ( 4 ), R = H, R′ = tBu ( 5 ), R = H, R′ = 1‐Ada ( 6 ), R = H, R′ = CPh3 ( 7 ), R = H, R′ = Ph ( 8 ), R = H, RR′ = 2,6‐iPr2Ph (= DIP) ( 10 ), R = H, R′ = 2,4,6‐Me3Ph (= Mes) ( 11 ), R = H, R′ = 2,4,6‐tBu3Ph (= Mes*)] ( 12 ), R = H, R′ = SiMe3 ( 13 ), and R, R′ = SiMe2Ph (1 4 ). 31P‐NMR spectra confirm that phosphaalkenes 2 – 7 and 10 – 14 are monomeric in solution; the structures of 7 , 10 , and 12 were determined by X‐ray crystallography. Freshly prepared (iPrMe2Si)2C=PN(H)Ph ( 8 ) is a monomer that dimerizes with (N→C) proton migration within several hours to the stable diazadiphosphetidine [(iPrMe2Si)2CHPNPh]2 ( 9 ). NMR‐scale reactions of deprotonated 5 and 13 with tBuiPrPCl provide by P–P bond formation the P‐phosphanyl iminophosphoranes [(iPrMe2Si)2C=](RN=)PPtBu(iPr) [R = tBu ( 15 ), R = Me3Si ( 17 )]. Deprotonated 5 and Me3GeCl deliver by N–Ge bond formation the aminophosphaalkene (iPrMe2Si)2C=PN(tBu)GeMe3 ( 20 ), which with elemental selenium 5 undergoes (N→C) proton migration to form the alkyl(imino)(seleno)phosphorane [(iPrMe2Si)2CH](tBuN=)P=Se ( 21 ), which is a selenium‐bridged cyclic dimer in the solid state. 相似文献