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1.
Synthesis, structure, and reactivity of carboranylamidinate‐based half‐sandwich iridium and rhodium complexes are reported for the first time. Treatment of dimeric metal complexes [{Cp*M(μ‐Cl)Cl}2] (M=Ir, Rh; Cp*=η5‐C5Me5) with a solution of one equivalent of nBuLi and a carboranylamidine produces 18‐electron complexes [Cp*IrCl(CabN‐DIC)] ( 1 a ; CabN‐DIC=[iPrN?C(closo‐1,2‐C2B10H10)(NHiPr)]), [Cp*RhCl(CabN‐DIC)] ( 1 b ), and [Cp*RhCl(CabN‐DCC)] ( 1 c ; CabN‐DCC=[CyN?C(closo‐1,2‐C2B10H10)(NHCy)]). A series of 16‐electron half‐sandwich Ir and Rh complexes [Cp*Ir(CabN′‐DIC)] ( 2 a ; CabN′‐DIC=[iPrN?C(closo‐1,2‐C2B10H10)(NiPr)]), [Cp*Ir(CabN′‐DCC)] ( 2 b , CabN′‐DCC=[CyN?C(closo‐1,2‐C2B10H10)(NCy)]), and [Cp*Rh(CabN′‐DIC)] ( 2 c ) is also obtained when an excess of nBuLi is used. The unexpected products [Cp*M(CabN,S‐DIC)], [Cp*M(CabN,S‐DCC)] (M=Ir 3 a , 3 b ; Rh 3 c , 3 d ), formed through BH activation, are obtained by reaction of [{Cp*MCl2}2] with carboranylamidinate sulfides [RN?C(closo‐1,2‐C2B10H10)(NHR)]S? (R=iPr, Cy), which can be prepared by inserting sulfur into the C? Li bond of lithium carboranylamidinates. Iridium complex 1 a shows catalytic activities of up to 2.69×106 gPNB ${{\rm{mol}}_{{\rm{Ir}}}^{ - {\rm{1}}} }Synthesis, structure, and reactivity of carboranylamidinate-based half-sandwich iridium and rhodium complexes are reported for the first time. Treatment of dimeric metal complexes [{Cp*M(μ-Cl)Cl}(2)] (M = Ir, Rh; Cp* = η(5)-C(5)Me(5)) with a solution of one equivalent of nBuLi and a carboranylamidine produces 18-electron complexes [Cp*IrCl(Cab(N)-DIC)] (1?a; Cab(N)-DIC = [iPrN=C(closo-1,2-C(2)B(10)H(10))(NHiPr)]), [Cp*RhCl(Cab(N)-DIC)] (1?b), and [Cp*RhCl(Cab(N)-DCC)] (1?c; Cab(N)-DCC = [CyN=C(closo-1,2-C(2)B(10)H(10))(NHCy)]). A series of 16-electron half-sandwich Ir and Rh complexes [Cp*Ir(Cab(N')-DIC)] (2?a; Cab(N')-DIC = [iPrN=C(closo-1,2-C(2)B(10)H(10))(NiPr)]), [Cp*Ir(Cab(N')-DCC)] (2?b, Cab(N')-DCC = [CyN=C(closo-1,2-C(2)B(10)H(10)(NCy)]), and [Cp*Rh(Cab(N')-DIC)] (2?c) is also obtained when an excess of nBuLi is used. The unexpected products [Cp*M(Cab(N,S)-DIC)], [Cp*M(Cab(N,S)-DCC)] (M = Ir 3?a, 3?b; Rh 3?c, 3?d), formed through BH activation, are obtained by reaction of [{Cp*MCl(2)}(2)] with carboranylamidinate sulfides [RN=C(closo-1,2-C(2)B(10)H(10))(NHR)]S(-) (R = iPr, Cy), which can be prepared by inserting sulfur into the C-Li bond of lithium carboranylamidinates. Iridium complex 1?a shows catalytic activities of up to 2.69×10(6) g(PNB) mol(Ir)(-1) h(-1) for the polymerization of norbornene in the presence of methylaluminoxane (MAO) as cocatalyst. Catalytic activities and the molecular weight of polynorbornene (PNB) were investigated under various reaction conditions. All complexes were fully characterized by elemental analysis and IR and NMR spectroscopy; the structures of 1?a-c, 2?a, b; and 3?a, b, d were further confirmed by single crystal X-ray diffraction. 相似文献
2.
Molecular and Crystal Structure of Bis[chloro(μ‐phenylimido)(η5‐pentamethylcyclopentadienyl)tantalum(IV)](Ta–Ta), [{TaCl(μ‐NPh)Cp*}2] Despite the steric hindrance of the central atom in [TaCl2(NPh)Cp*] (Ph = C6H5, Cp* = η5‐C5(CH3)5), caused by the Cp* ligand, the imido‐ligand takes a change in bond structure when this educt is reduced to the binuclear complex [{TaCl(μ‐NPh)Cp*}2] in which tantalum is stabilized in the unusual oxidation state +4. 相似文献
3.
Peng‐Fei Cui Yang Gao Shu‐Ting Guo Yue‐Jian Lin Zhen‐Hua Li Guo‐Xin Jin 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(24):8213-8217
In this work, a pincer‐type complex [Cp*Ir‐(SNPh)(SNHPh)(C2B10H9)] ( 2 ) was synthesized and its reactivity studied in detail. Interestingly, molecular hydrogen can induce the transformation between the metalloradical [Cp*Ir‐(SNPh)2(C2B10H9)] ( 5 .) and 2 . A mixed‐valence complex, [(Cp*Ir)2‐(SNPh)2(C2B10H8)] ( 7 .+), was also synthesized by one‐electron oxidation. Studies show that 7 .+ is fully delocalized, possessing a four‐centered‐one‐electron (S‐Ir‐Ir‐S) bonding interaction. DFT calculations were also in good agreement with the experimental results. 相似文献
4.
Taishin Takamura Takuya Harada Tatsuro Furuta Takao Ikariya Shigeki Kuwata 《化学:亚洲杂志》2020,15(1):72-78
Synthesis and deprotonation reactions of half‐sandwich iridium complexes bearing a vicinal dioxime ligand were studied. Treatment of [{Cp*IrCl(μ‐Cl)}2] (Cp*=η5‐C5Me5) with dimethylglyoxime (LH2) at an Ir:LH2 ratio of 1:1 afforded the cationic dioxime iridium complex [Cp*IrCl(LH2)]Cl ( 1 ). The chlorido complex 1 undergoes stepwise and reversible deprotonation with potassium carbonate to give the oxime–oximato complex [Cp*IrCl(LH)] ( 2 ) and the anionic dioximato(2?) complex K[Cp*IrCl(L)] ( 3 ) sequentially. Meanwhile, twofold deprotonation of the sulfato complex [Cp*Ir(SO4)(LH2)] ( 4 ) resulted in the formation of the oximato‐bridged dinuclear complex [{Cp*Ir(μ‐L)}2] ( 5 ). X‐ray analyses disclosed their supramolecular structures with one‐dimensional infinite chain ( 1 and 2 ), hexagonal open channels ( 3 ), and a tetrameric rhomboid ( 4 ) featuring multiple intermolecular hydrogen bonds and electrostatic interactions. 相似文献
5.
Reactions of Cp*NbCl4 and Cp*TaCl4 with Trimethylsilyl‐azide, Me3Si‐N3. Molecular Structures of the Bis(azido)‐Oxo‐Bridged Complexes [Cp*NbCl(N3)(μ‐N3)]2(μ‐O) and [Cp*TaCl2(μ‐N3)]2(μ‐O) (Cp* = Pentamethylcyclopentadienyl) The chloro ligands in Cp*TaCl4 (1c) can be stepwise substituted for azido ligands by reactions with trimethylsilyl azide, Me3Si‐N3 (A) , to generate the complete series of the bis(azido)‐bridged dimers [Cp*TaCl3‐n(N3)n(μ‐N3)]2 ( n = 0 (2c) , n = 1 (3c) , n = 2 (4c) and n = 3 (5c) ). If the solvent CH2Cl2 contains traces of water, an additional oxo bridge is incorporated to give [Cp*‐TaCl2(μ‐N3)]2(μ‐O) (6c) or [Cp*TaCl(N3)(μ‐N3)]2(μ‐O) (7c) , respectively. Both 6c and 7c are also formed in stoichiometric reactions from [Cp*TaCl2(μ‐OH)]2(μ‐O) (8c) and A . Analogous reactions of Cp*NbCl4 (1b) with A were used to prepare the azide‐rich dinuclear products [Cp*NbCl3‐n(N3)n(μ‐N3)]2 (n = 2 (4b) , and n = 3 (5b) ), and [Cp*NbCl(N3)(μ‐N3)]2(μ‐O) (7b) . The mononuclear complex Cp*Ta(N3)Me3 (10c) is obtained from Cp*Ta(Cl)Me3 and A . All azido complexes were characterised by their IR as well as their 1H and 13C NMR spectra; X‐ray crystal structure analyses are available for 6c and 7b . 相似文献
6.
A series of binuclear complexes [{Cp*Ir(OOCCH2COO)}2(pyrazine)] ( 1 b ), [{Cp*Ir(OOCCH2COO)}2(bpy)] ( 2 b ; bpy=4,4′‐bipyridine), [{Cp*Ir(OOCCH2COO)}2(bpe)] ( 3 b ; bpe=trans‐1,2‐bis(4‐pyridyl)ethylene) and tetranuclear metallamacrocycles [{(Cp*Ir)2(OOC‐C?C‐COO)(pyrazine)}2] ( 1 c ), [{(Cp*Ir)2(OOC‐C?C‐COO)(bpy)}2] ( 2 c ), [{(Cp*Ir)2(OOC‐C?C‐COO)(bpe)}2] ( 3 c ), and [{(Cp*Ir)2[OOC(H3C6)‐N?N‐(C6H3)COO](pyrazine)}2] ( 1 d ), [{(Cp*Ir)2[OOC(H3C6)‐N?N‐(C6H3)COO](bpy)}2] ( 2 d ), [{(Cp*Ir)2[OOC(H3C6)‐N?N‐(C6H3)COO](bpe)}2] ( 3 d ) were formed by reactions of 1 a – 3 a {[(Cp*Ir)2(pyrazine)Cl2] ( 1 a ), [(Cp*Ir)2(bpy)Cl2] ( 2 a ), and [(Cp*Ir)2(bpe)Cl2] ( 3 a )} with malonic acid, fumaric acid, or H2ADB (azobenzene‐4,4′‐chcarboxylic acid), respectively, under mild conditions. The metallamacrocycles were directly self‐assembled by activation of C? H bonds from dicarboxylic acids. Interestingly, after exposure to UV/Vis light, 3 c was converted to [2+2] cycloaddition complex 4 . The molecular structures of 2 b , 1 c , 1 d , and 4 were characterized by single‐crystal x‐ray crystallography. Nanosized tubular channels, which may play important roles for their stability, were also observed in 1 c , 1 d , and 4 . All complexes were well characterized by 1H NMR and IR spectroscopy, as well as elemental analysis. 相似文献
7.
Study of the Bonding Modes of Di‐2‐pyridyl ketoxime Ligand towards Ruthenium,Rhodium and Iridium Half Sandwich Complexes
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The bonding modes of the ligand di‐2‐pyridyl ketoxime towards half‐sandwich arene ruthenium, Cp*Rh and Cp*Ir complexes were investigated. Di‐2‐pyridyl ketoxime {pyC(py)NOH} react with metal precursor [Cp*IrCl2]2 to give cationic oxime complexes of the general formula [Cp*Ir{pyC(py)NOH}Cl]PF6 ( 1a ) and [Cp*Ir{pyC(py)NOH}Cl]PF6 ( 1b ), for which two coordination isomers were observed by NMR spectroscopy. The molecular structures of the complexes revealed that in the major isomer the oxime nitrogen and one of the pyridine nitrogen atoms are coordinated to the central iridium atom forming a five membered metallocycle, whereas in the minor isomer both the pyridine nitrogen atoms are coordinated to the iridium atom forming a six membered metallacyclic ring. Di‐2‐pyridyl ketoxime react with [(arene)MCl2]2 to form complexes bearing formula [(p‐cymene)Ru{pyC(py)NOH}Cl]PF6 ( 2 ); [(benzene)Ru{pyC(py)NOH}Cl]PF6 ( 3 ), and [Cp*Rh{pyC(py)NOH}Cl]PF6 ( 4 ). In case of complex 3 the ligand coordinates to the metal by using oxime nitrogen and one of the pyridine nitrogen atoms, whereas in complex 4 both the pyridine nitrogen atoms are coordinated to the metal ion. The complexes were fully characterized by spectroscopic techniques. 相似文献
8.
Transformation of a Cp*–Iridium(III) Precatalyst for Water Oxidation when Exposed to Oxidative Stress
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Dr. Cristiano Zuccaccia Prof. Gianfranco Bellachioma Prof. Olga Bortolini Alberto Bucci Arianna Savini Prof. Dr. Alceo Macchioni 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(12):3446-3456
The reaction of [Cp*Ir(bzpy)NO3] ( 1 ; bzpy=2‐benzoylpyridine, Cp*=pentamethylcyclopentadienyl anion), a competent water‐oxidation catalyst, with several oxidants (H2O2, NaIO4, cerium ammonium nitrate (CAN)) was studied to intercept and characterize possible intermediates of the oxidative transformation. NMR spectroscopy and ESI‐MS techniques provided evidence for the formation of many species that all had the intact Ir–bzpy moiety and a gradually more oxidized Cp* ligand. Initially, an oxygen atom is trapped in between two carbon atoms of Cp* and iridium, which gives an oxygen–Ir coordinated epoxide, whereas the remaining three carbon atoms of Cp* are involved in a η3 interaction with iridium ( 2 a ). Formal addition of H2O to 2 a or H2O2 to 1 leads to 2 b , in which a double MeCOH functionalization of Cp* is present with one MeCOH engaged in an interaction with iridium. The structure of 2 b was unambiguously determined in the solid state and in solution by X‐ray single‐crystal diffractometry and advanced NMR spectroscopic techniques, respectively. Further oxidation led to the opening of Cp* and transformation of the diol into a diketone with one carbonyl coordinated at the metal ( 2 c ). A η3 interaction between the three non‐oxygenated carbons of “ex‐Cp*” and iridium is also present in both 2 b and 2 c . Isolated 2 b and mixtures of 2 a – c species were tested in water‐oxidation catalysis by using CAN as sacrificial oxidant. They showed substantially the same activity than 1 (turnover frequency values ranged from 9 to 14 min?1). 相似文献
9.
Dr. Xian‐Kuan Huo Ge Su Prof. Dr. Guo‐Xin Jin 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(39):12017-12027
Monophosphine‐o‐carborane has four competitive coordination modes when it coordinates to metal centers. To explore the structural transitions driven by these competitive coordination modes, a series of monophosphine‐o‐carborane Ir,Rh complexes were synthesized and characterized. [Cp*M(Cl)2{1‐(PPh2)‐1,2‐C2B10H11}] (M=Ir ( 1 a ), Rh ( 1 b ); Cp*=η5‐C5Me5), [Cp*Ir(H){7‐(PPh2)‐7,8‐C2B9H11}] ( 2 a ), and [1‐(PPh2)‐3‐(η5‐Cp*)‐3,1,2‐MC2B9H10] (M=Ir ( 3 a ), Rh ( 3 b )) can be all prepared directly by the reaction of 1‐(PPh2)‐1,2‐C2B10H11 with dimeric complexes [(Cp*MCl2)2] (M=Ir, Rh) under different conditions. Compound 3 b was treated with AgOTf (OTf=CF3SO3?) to afford the tetranuclear metallacarborane [Ag2(thf)2(OTf)2{1‐(PPh2)‐3‐(η5‐Cp*)‐3,1,2‐RhC2B9H10}2] ( 4 b ). The arylphosphine group in 3 a and 3 b was functionalized by elemental sulfur (1 equiv) in the presence of Et3N to afford [1‐{(S)PPh2}‐3‐(η5‐Cp*)‐3,1,2‐MC2B9H10] (M=Ir ( 5 a ), Rh ( 5 b )). Additionally, the 1‐(PPh2)‐1,2‐C2B10H11 ligand was functionalized by elemental sulfur (2 equiv) and then treated with [(Cp*IrCl2)2], thus resulting in two 16‐electron complexes [Cp*Ir(7‐{(S)PPh2}‐8‐S‐7,8‐C2B9H9)] ( 6 a ) and [Cp*Ir(7‐{(S)PPh2}‐8‐S‐9‐OCH3‐7,8‐C2B9H9)] ( 7 a ). Compound 6 a further reacted with nBuPPh2, thereby leading to 18‐electron complex [Cp*Ir(nBuPPh2)(7‐{(S)PPh2}‐8‐S‐7,8‐C2B9H10)] ( 8 a ). The influences of other factors on structural transitions or the formation of targeted compounds, including reaction temperature and solvent, were also explored. 相似文献
10.
Dr. Ann‐Katrin Jungton Dr. Christian Herwig Prof. Dr. Thomas Braun Prof. Dr. Christian Limberg 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(32):10009-10013
1H NMR exchange spectroscopy of a reaction mixture of [Cp*Ir(H)4] ( 1 ; Cp*=1,2,3,4,5‐pentamethylcyclopentadienyl) and ammonia suggests an exchange of hydrogen atoms between the hydrido ligands and ammonia. Treatment of 1 with ND3 led to an H/D exchange between ND3 and the hydrido ligands of 1 . Subsequent studies showed that photolysis of 1 isolated in frozen argon matrices leads to the formation of the iridium compounds [Cp*Ir(H)2] ( 2 ) and [Cp*Ir(H)3] ( 4 ), as it was confirmed by IR spectroscopy. In the presence of water the aqua complex [Cp*Ir(H)2(OH2)] ( 3 ) was generated simultaneously. Accordingly, photolysis of 1 in an argon matrix doped with ammonia gave rise to the ammine complex [Cp*Ir(H)2(NH3)] ( 5 ). IR assignments were supported by calculations of the gas‐phase IR spectra of 1 – 5 by DFT methods. 相似文献
11.
C(sp3)H Activation without a Directing Group: Regioselective Synthesis of N‐Ylide or N‐Heterocyclic Carbene Complexes Controlled by the Choice of Metal and Ligand
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Dr. Warren B. Cross Sunnah Razak Kuldip Singh Andrew J. Warner 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(41):13203-13209
N‐Ylide complexes of Ir have been generated by C(sp3)?H activation of α‐pyridinium or α‐imidazolium esters in reactions with [Cp*IrCl2]2 and NaOAc. These reactions are rare examples of C(sp3)?H activation without a covalent directing group, which—even more unusually—occur α to a carbonyl group. For the reaction of the α‐imidazolium ester [ 3 H]Cl, the site selectivity of C?H activation could be controlled by the choice of metal and ligand: with [Cp*IrCl2]2 and NaOAc, C(sp3)?H activation gave the N‐ylide complex 4 ; in contrast, with Ag2O followed by [Cp*IrCl2]2, C(sp2)?H activation gave the N‐heterocyclic carbene complex 5 . DFT calculations revealed that the N‐ylide complex 4 was the kinetic product of an ambiphilic C?H activation. Examination of the computed transition state for the reaction to give 4 indicated that unlike in related reactions, the acetate ligand appears to play the dominant role in C?H bond cleavage. 相似文献
12.
Dr. Mandeep Kaur Dr. Noor U Din Reshi Kamaless Patra Arindom Bhattacherya Dr. Sooraj Kunnikuruvan Prof. Jitendra K. Bera 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(41):10737-10748
A Cp*Ir(III) complex ( 1 ) of a newly designed ligand L1 featuring a proton-responsive pyridyl(benzamide) appended on N - heterocyclic carbene (NHC) has been synthesized. The molecular structure of 1 reveals a dearomatized form of the ligand. The protonation of 1 with HBF4 in tetrahydrofuran gives the corresponding aromatized complex [Cp*Ir(L1H)Cl]BF4 ( 2 ). Both compounds are characterized spectroscopically and by X-ray crystallography. The protonation of 1 with acid is examined by 1H NMR and UV-vis spectra. The proton-responsive character of 1 is exploited for catalyzing α-alkylation of ketones and β-alkylation of secondary alcohols using primary alcohols as alkylating agents through hydrogen-borrowing methodology. Compound 1 is an effective catalyst for these reactions and exhibits a superior activity in comparison to a structurally similar iridium complex [Cp*Ir(L2)Cl]PF6 ( 3 ) lacking a proton-responsive pendant amide moiety. The catalytic alkylation is characterized by a wide substrate scope, low catalyst and base loadings, and a short reaction time. The catalytic efficacy of 1 is also demonstrated for the syntheses of quinoline and lactone derivatives via acceptorless dehydrogenation, and selective alkylation of two steroids, pregnenolone and testosterone. Detailed mechanistic investigations and DFT calculations substantiate the role of the proton-responsive ligand in the hydrogen-borrowing process. 相似文献
13.
Bio‐Inspired Transition Metal–Organic Hydride Conjugates for Catalysis of Transfer Hydrogenation: Experiment and Theory
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Alex McSkimming Dr. Bun Chan Dr. Mohan M. Bhadbhade Dr. Graham E. Ball Prof. Stephen B. Colbran 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(7):2821-2834
Taking inspiration from yeast alcohol dehydrogenase (yADH), a benzimidazolium (BI+) organic hydride‐acceptor domain has been coupled with a 1,10‐phenanthroline (phen) metal‐binding domain to afford a novel multifunctional ligand ( L BI+) with hydride‐carrier capacity ( L BI++H?? L BIH). Complexes of the type [Cp*M( L BI)Cl][PF6]2 (M=Rh, Ir) have been made and fully characterised by cyclic voltammetry, UV/Vis spectroelectrochemistry, and, for the IrIII congener, X‐ray crystallography. [Cp*Rh( L BI)Cl][PF6]2 catalyses the transfer hydrogenation of imines by formate ion in very goods yield under conditions where the corresponding [Cp*Ir( L BI)Cl][PF6] and [Cp*M(phen)Cl][PF6] (M=Rh, Ir) complexes are almost inert as catalysts. Possible alternatives for the catalysis pathway are canvassed, and the free energies of intermediates and transition states determined by DFT calculations. The DFT study supports a mechanism involving formate‐driven Rh?H formation (90 kJ mol?1 free‐energy barrier), transfer of hydride between the Rh and BI+ centres to generate a tethered benzimidazoline (BIH) hydride donor, binding of imine substrate at Rh, back‐transfer of hydride from the BIH organic hydride donor to the Rh‐activated imine substrate (89 kJ mol?1 barrier), and exergonic protonation of the metal‐bound amide by formic acid with release of amine product to close the catalytic cycle. Parallels with the mechanism of biological hydride transfer in yADH are discussed. 相似文献
14.
Dr. Jean‐Pierre Djukic Wissam Iali Dr. Michel Pfeffer Dr. Xavier‐Frédéric Le Goff 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(19):6063-6078
Facial selectivity during the π‐coordination of pseudo‐tetrahedral iridacycles by neutral (Cr(CO)3), monocationic (Cp*Ru+), and biscationic (Cp*Ir2+) metal centers was directly influenced by the coulombic imbalance in the coordination sphere of the chelated Ir center. We also showed by using theoretical calculations that the feasibility of the related metallacycles that displayed metallocenic planar chirality was dependent to the presence of an electron‐donating group, such as NMe2, which contributed to the overall stability of the complexes. When the π‐bonded moiety was the strongly electron‐withdrawing Cp*Ir2+ group, the electron donation from NMe2 resulted in major conformational changes, with a barrier to rotation of about 17 kcal mol?1 for this group that became spectroscopically diastereotopic (high‐field 1H NMR spectroscopy). This peculiar property is proposed as a means to introduce a new type of constitutional chirality at the nitrogen center: planar chirality at tertiary aromatic amines. 相似文献
15.
Chemistry of N,S‐Heterocyclic Carbene and Metallaboratrane Complexes: A New η3‐BCC‐Borataallyl Complex
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Dr. Dipak Kumar Roy Anangsha De Subhankar Panda Dr. Babu Varghese Prof. Sundargopal Ghosh 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(39):13732-13738
A high‐yielding synthetic route for the preparation of group 9 metallaboratrane complexes [Cp*MBH(L)2], 1 and 2 ( 1 , M=Rh, 2 , M=Ir; L=C7H4NS2) has been developed using [{Cp*MCl2}2] as precursor. This method also permitted the synthesis of an Rh–N,S‐heterocyclic carbene complex, [(Cp*Rh)(L2)(1‐benzothiazol‐2‐ylidene)] ( 3 ; L=C7H4NS2) in good yield. The reaction of compound 3 with neutral borane reagents led to the isolation of a novel borataallyl complex [Cp*Rh(L)2B{CH2C(CO2Me)}] ( 4 ; L=C7H4NS2). Compound 4 features a rare η3‐interaction between rhodium and the B‐C‐C unit of a vinylborane moiety. Furthermore, with the objective of generating metallaboratranes of other early and late transition metals through a transmetallation approach, reactions of rhoda‐ and irida‐boratrane complexes with metal carbonyl compounds were carried out. Although the objective of isolating such complexes was not achieved, several interesting mixed‐metal complexes [{Cp*Rh}{Re(CO)3}(C7H4NS2)3] ( 5 ), [Cp*Rh{Fe2(CO)6}(μ‐CO)S] ( 6 ), and [Cp*RhBH(L)2W(CO)5] ( 7 ; L=C7H4NS2) have been isolated. All of the new compounds have been characterized in solution by mass spectrometry, IR spectroscopy, and 1H, 11B, and 13C NMR spectroscopies, and the structural types of 4 – 7 have been unequivocally established by crystallographic analysis. 相似文献
16.
Prof. Dr. Stephan Schulz Sarah Schmidt Dieter Bläser Christoph Wölper 《无机化学与普通化学杂志》2012,638(11):1705-1710
Zincocene Cp*2Zn reacts with carbodiimides C(NR)2 with insertion into the Zn–Cp* bond and formation of [(Cp*C(NR)2]2Zn [R = Et ( 1 ), iPr ( 2 ), Cy ( 3 )]. In addition, the reaction of Cp*2Zn with CS2 under dry conditions gives (Cp*CS2)2Zn ( 4 ), whereas in the presence of a small amount of water [Zn4(μ4‐O)(S2CCp*)6] ( 5 ) is obtained. Compounds 1 – 4 were characterized by NMR (1H, 13C) and IR spectroscopy as well as elemental analysis and single‐crystal X‐ray diffraction ( 2 – 4 , 5 of poor quality). The solid‐state structure of 5 is comparable to the carboxylate complex previously obtained from the reaction of Cp*2Zn with CO2. 相似文献
17.
The reactions of Cp*M(PMe3)Cl2 (M = Rh ( 1a ), Ir ( 1b )) with (NEt4)2[WS4] led to the heterodimetallic sulfido‐bridged complexes Cp*M(PMe3)[(μ‐S)2WS2] (M = Rh ( 2a ), Ir ( 2b )), whereas the dimers [Cp*MCl(μ‐Cl)]2 (M = Rh ( 4a ), Ir ( 4b )) reacted with (NEt4)2[WS4) to give the known trinuclear compounds [Cp*M(Cl)]2(μ‐WS4) (M = Rh ( 5a ), Ir ( 5b )). Hydrolysis of the terminal W=S bonds converts 2a, b into Cp*M(PMe3)[(μ‐S)2WO2] (M = Rh ( 3a ), Ir ( 3b )). Salts of a heterodimetallic anion, A[CpMo(I)(NO)(WS4)] ( 6 ) (A+ = NEt4+, NPh4+) were obtained by reactions of [CpMo(NO)I2]2 with tetrathiotungstates, A2[WS4]. The complexes were characterized by IR and NMR (1H, 13C, 31P) spectroscopy, and the X‐ray crystallographic structure of Cp*Rh(PMe3)[(μ‐S)2WS2] ( 2a ) has been determined. The bond lengths and angles in the coordinations spheres of Rh and W in 2a (Rh···W 288.5(1) pm) are compared with related complexes containing terminal [WS42—] chelate ligands. 相似文献
18.
Reactions of Group 4 Metallocenes with Monosubstituted Acetonitriles: Keteniminate Formation versus CC Coupling
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Lisanne Becker Dr. Martin Haehnel Dr. Anke Spannenberg Dr. Perdita Arndt Dr. Uwe Rosenthal 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(8):3242-3248
The reactions of the Group 4 metallocene dichlorides [Cp′2MCl2] ( 1 a : M=Ti, Cp′=Cp*=η5‐pentamethylcyclopentadienyl, 1 b : M=Zr, Cp′=Cp=η5‐cyclopentadienyl) with lithiated MesCH2?C?N gave [Cp*2TiCl(N=C=C(HMes))] ( 3 ; Mes=mesityl) in the case of 1 a . For compound 1 b , a nitrile–nitrile coupling resulted in a five‐membered bridge in 4 . The reaction of the metallocene alkyne complex [Cp*2Zr(η2‐Me3SiC2SiMe3)] ( 2 ) with PhCH2?C?N led in the first step to the unstable product [Cp*2Zr(η2‐Me3SiC2SiMe3)(NC?CH2Ph)] ( 5 ). After the elimination of the alkyne, a mixture of products was formed. By variation of the solvent and the reaction temperature, three compounds were isolated: a diazadiene complex 6 , a bis(keteniminate) complex 7 , and 8 with a keteniminate ligand and a five‐membered metallacycle. Subsequent variation of the Cp ligand and the metal center by using [Cp2Zr] and [Cp*2Ti] with Me3SiC2SiMe3 in the reactions with PhCH2?C?N gave complex mixtures. 相似文献
19.
Oxidative C−H/C−H Cross‐Coupling Reactions between N‐Acylanilines and Benzamides Enabled by a Cp*‐Free RhCl3/TFA Catalytic System
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Yang Shi Luoqiang Zhang Prof. Dr. Jingbo Lan Min Zhang Fulin Zhou Wenlong Wei Prof. Dr. Jingsong You 《Angewandte Chemie (International ed. in English)》2018,57(29):9108-9112
By making use of a dual‐chelation‐assisted strategy, a completely regiocontrolled oxidative C?H/C?H cross‐coupling reaction between an N‐acylaniline and a benzamide has been accomplished for the first time. This process constitutes a step‐economic and highly efficient pathway to 2‐amino‐2′‐carboxybiaryl scaffolds from readily available substrates. A Cp*‐free RhCl3/TFA catalytic system was developed to replace the [Cp*RhCl2]2/AgSbF6 system generally used in oxidative C?H/C?H cross‐coupling reactions between two (hetero)arenes (Cp*=pentamethylcyclopentadienyl, TFA=trifluoroacetic acid). The RhCl3/TFA system avoids the use of the expensive Cp* ligand and AgSbF6. As an illustrative example, the procedure developed herein greatly streamlines the total synthesis of the naturally occurring benzo[c]phenanthridine alkaloid oxynitidine, which was accomplished in excellent overall yield. 相似文献
20.
Martin Piesch Stephan Reichl Michael Seidl Gbor Balzs Manfred Scheer 《Angewandte Chemie (International ed. in English)》2019,58(46):16563-16568
The reaction of [Cp′′′Co(η4‐P4)] ( 1 ) (Cp′′′=1,2,4‐tBu3C5H2) with MeNHC (MeNHC=1,3,4,5‐tetramethylimidazol‐2‐ylidene) leads through NHC‐induced phosphorus cation abstraction to the ring contraction product [(MeNHC)2P][Cp′′′Co(η3‐P3)] ( 2 ), which represents the first example of an anionic CoP3 complex. Such NHC‐induced ring contraction reactions are also applicable for triple‐decker sandwich complexes. The complexes [(Cp*Mo)2(μ,η6:6‐E6)] ( 3 a , 3 b ) (Cp*=C5Me5; E=P, As) can be transformed to the complexes [(MeNHC)2E][(Cp*M)2(μ,η3:3‐E3)(μ,η2:2‐E2)] ( 4 a , 4 b ), with 4 b representing the first structurally characterized example of an NHC‐substituted AsI cation. Further, the reaction of the vanadium complex [(Cp*V)2(μ,η6:6‐P6)] ( 5 ) with MeNHC results in the formation of the unprecedented complexes [(MeNHC)2P][(Cp*V)2(μ,η6:6‐P6)] ( 6 ), [(MeNHC)2P][(Cp*V)2(μ,η5:5‐P5)] ( 7 ) and [(Cp*V)2(μ,η3:3‐P3)(μ,η1:1‐P{MeNHC})] ( 8 ). 相似文献