Showing papers by "George M. Sheldrick published in 1987"
61 citations
TL;DR: Carbene-Analgous Reactions of the Products of Dehalogenation of Dichloro-diisopropylamino)borane with Aromatic Compounds and 1,2-Dimethoxyethane as discussed by the authors.
Abstract: Carbene-Analgous Reactions of the Products of Dehalogenation of Dichloro(diisopropylamino)borane with Aromatic Compounds and 1,2-Dimethoxyethane
Sodium complexes of aromatic compounds in 1,2-dimethoxyethane react with dichloro-diisopropylamino)borane to give compounds formed via carben(oidal) intermediates: From naphthalene 1,2-bis(diisopropylamino)-1,1a,2,8b-tetrahydroborireno[2,3-b][3]benzoborepine (1) is formed. From acenaphthylene 2-(diisopropylamino)-2,3-dihydro-1H-naphtho[1,8-cd]borine (2) and with 1-methylnaphthalene, in addition to 1,2-bis[(diisopropylamino)methoxyboryl]ethyne (3), (diisopropylamino)dimethoxyborane (4) is isolated. 1H-, 11B-, 13C-, 14N-, 15N NMR and MS data are given. For 3 the X-ray structure is reported.
32 citations
TL;DR: In this paper, the crystal structure of the dimeric lithium derivative of di-tert-butyl(rm-butylamino)fluorosilane, each lithium atom is coordinated by one fluorine and two nitrogen atoms.
Abstract: Depending on the solvent and the bulkiness of the substituents, Iithiated aminofluorosilanes are dimers, monomers, or LiF-adducts of iminosilanes. In the crystal structure of the dimeric lithium derivative of di-tert-butyl(rm-butylamino)fluorosilane, each lithium atom is coordinated by one fluorine and two nitrogen atoms. LiF-elimination leads - if sterically possible - to dimerisation. The limits of dimerisation are reached with the dimer diisopropyl(tri-tert-butylphenyI- imino)silane, for which the crystal structure analysis shows severe steric distortions. Fluorine- chlorine-cxchange occurs in reactions of lithiated (tri-tert-butylphenylimino)fluorosilanes with Me₃SiCl. Iminosilanes are obtained by thermal LiCl-elimination from the resulting salts.
22 citations
TL;DR: The linear phosphazene [H2NPPh2NP Ph2NH2]Cl(1) reacts with MoCl3N and NbCl5 to form the new cyclometallaphosphazenes [graphic omitted]oCl3(3) and bCl2(4), respectively as discussed by the authors.
Abstract: The linear phosphazene [H2NPPh2NPPh2NH2]Cl(1) reacts with MoCl3N and NbCl5 to form the new cyclometallaphosphazenes [graphic omitted]oCl3(3) and [graphic omitted]bCl2(4), respectively. The crystal structure of the acetonitrile adduct of the cyclomolybdaphosphazene (3) shows that the central six-membered ring is nearly planar.
16 citations
TL;DR: In this paper, the crystal structure determination shows that 14a is a dimer with planar three-coordinated lithium and nitrogen atoms, while 14b and 14c are sturcutral isomers and are formed by 1,3-silyl group migration of lithiated 4.
Abstract: 1,3-Funktionelle Siloxane [(CMe3)2SiR – O – SiR′2Hal, ROH, HalCl, R′=CHMe2 (3); RNH2, HalF, R′=CHMe2 (4), R′=CMe3 (5)] werden durch Reaktion der Dihalogensilane mit lithiiertem Diol 1 und Aminosilanol 2 erhalten. Die Lithiumsalze von 3 und 4 verlieren thermisch LiHal unter Bildung achtgliedriger (SiO)- (6) bzw. (SiNSiO)-Ringe (7). Substitutionen von 4 und 5 mit Halogensilanen fuhren zur Bildung der 1-(Silylamino)disiloxane 8 – 14. Die Verbindungen 11 und 13 sowie 12 und 14 sind Strukturisomere, die durch 1,3-Silylgruppenwanderung beim lithiierten 4 entstehen. Die durch Anwesenheit von Difluorsilanen katalysierte, intramolekulare Cyclisierung von 8 und 10 stellt eine gezielte Synthese fur 1-Oxa-3-aza-2,4-disilacyclobutane (15, 16) dar. Die Lithiumderivate von 9 und 14 – 9a und 14a – zeigen keine Tendenz zur LiF-Eliminierung. Nach der Kristallstrukturanalyse ist 14a ein Dimer mit planaren dreifach koordinierten Lithium- und Stickstoffatomen.
1,3-Functional siloxanes [(CMe3)2SiR – O – SiR′2Hal, ROH, HalCl, R′=CHMe2 (3); RNH2, HalF, R′=CHMe2 (4), R′=CMe3 (5)] are obtained in the reaction of dihalogenosilanes with the lithiated diol 1 and the aminosilanols 2, respectively. The lithium salts of 3 and 4 lose LiHal thermally to give eight-membered (SiO) (6) or (SiNSiO) (7) rings. Substitutions of 4 and 5 with halogenosilanes lead to the formation of the 1-(silylamino)disiloxanes 8 – 14. Compounds 11 and 13 as well as 12 and 14 are sturcutral isomers and are formed by 1,3-silyl group migration of lithiated 4. The intramolecular cyclisation of 8 and 10, which is catalysed by the presence of fluorosilanes, is a direct synthesis of 1-oxa-3-aza-2,4-disilacyclobutanes (15, 16). The lithium derivatives of 9 and 14, 9a and 14a, show no tendency to eliminate LiF. The crystal structure determination shows that 14a is a dimer with planar three-coordinated lithium and nitrogen atoms.
12 citations
TL;DR: In this paper, an X-ray single structure analysis of transition metal halides with derivatives of Dimethylsulfoximine is presented. But this analysis is restricted to the case where the transition metal is a transition metal and the derivatives are derived from Dimethyl sulfoxideimine.
Abstract: WF6 reagiert mit Me2S(O)NSiMe3 (1) im Molverhaltnis 1:1 zu F5WNS(O)Me2, das mit 1 zu F4W[NS(O)Me2]2 (3) umgesetzt wird 2 und 3 werden u. a. durch Rontgenstrukturanalysen charakterisiert. In diesen Verbindungen besteht ein Mehrfachbindungsteil zwischen N und W. Mit Me2S(O)NLi reagiert 3 unter Substitution eines weiteren Fluoratoms zu F3W[NS(O)Me2]3 (4). Cl4W[NS(O)Me2]2 (5) und Cl4MoNS(O)Me2 · CH3CN (6) entstehen bei der Umsetzung von WCl6 und MoCl5 mit 1.
Reactions of Transition Metal Halides with Derivatives of Dimethylsulfoximine – X-Ray Single Structure Analysis of F5WNS(O)Me2 und F4[NS(O)Me2]2
WF6 reacts with Me2S(O)NSiMe3 (1) in a molar ratio 1:1 to give F5WNS(O)Me2 (2), which reacts further with 1 to yield F4W[NS(O)Me2]2 (3). 2 and 3 were characterized i. a. by X-ray crystal structure analyses. In these compounds there is evidence of multiple bonding between N and W. Reaction of 3 with Me2S(O)NLi leads to substitution of a further fluorine atom with formation of F3W[NS(O)Me2]3 (4). Cl4W[NS(O)Me2]2 (5) and Cl4MoNS(O)Me2 · CH3CN (6) are formed by the reaction of WCl6 and MoCl5 with 1.
9 citations
TL;DR: In this article, the reaction of cyanogen with secondary amines at low temperatures leads to N-dialkylformamidines, which react further with 2,2,4,4-tetrakis(trifluoromethyl) -1,3-dithiane to yield substituted 2,5-dihydro-5-imino-2,2-bis(trifi-ormethyl)- thiazole derivatives 1 and 2.
8 citations
TL;DR: The bisthionylimide complex [Cp2Ti(NSO)2]-Cp = η5-C5H5] was prepared by reaction of [C p2TiCl2] and KNSO and its X-ray crystal structure determined as discussed by the authors.
Abstract: The bisthionylimide complex [Cp2Ti(NSO)2](Cp =η5-C5H5) was prepared by reaction of [Cp2TiCl2] and KNSO and its X-ray crystal structure determined; reaction of this compound with LiN(SiMe3)2 yielded [Cp2Ti(NSNSiMe3)2].
6 citations
TL;DR: In this paper, a dark red air stable complex (PhAsNSN)2 (1) reacts with M(CO)4(C7H8) (M = a Cr. b Mo) to yield PhAs NSN 2 (2) (1), which exhibits approximate mm symmetry with mean bond lengths: Mo-As 255.1.
Abstract: (PhAsNSN)2 (1) reacts with M(CO)4(C7H8) (M = a Cr. b Mo) to yield (PhAsNSN)2M(CO)4 (2). 2a and 2b are dark red air stable complexes. 2b was characterized by X-ray diffraction. Crystals of 2b are monoclinic, space group C2/c, with a = 2884.7(4). b = 1166.2(2), c = 1344.1(2) pm, fβ = 104.81(2)° and Z = 8. The molecule exhibits approximate mm (C2v) symmetry with mean bond lengths: Mo-As 255.1. Mo-C 201.8. As-N 186.2 and S -N 152.8 pm.
5 citations
TL;DR: In this paper, a H2N-SO2 -NWCl4 (1) was synthesized from WCl6 and SO2(NH2)2, and formed adducts with donor solvents such as pyridine and acetonitrile.
Abstract: Abstract H2N-SO2 -NWCl4 (1) has been synthesized from WCl6 and SO2(NH2)2 , and forms adducts with donor solvents such as pyridine and acetonitrile. 1·CH3CN crystallizes in the space group P21/n with cell constants a = 652.5(1); b = 2325.3(2); c = 775.8(1) pm; β = 90.32(1)°. The nitrogen-tungsten bond length of 173.0 pm and the S-N-W bond angle of 169.3° indicate a W=N double bond.
5 citations
TL;DR: The reaction of ClSCF₂CF�SCl and (Me₃SiN) ₂SR₆ proceeds with formation of the seven-membered ring compounds 4a, R = CH₰, and 4b,R = C₁H₅ as discussed by the authors.
Abstract: The reaction of ClSCF₂CF₂SCl and (Me₃SiN)₂SR₂ proceeds with formation of the seven-membered ring compounds 4a, R = CH₃, and 4b, R = C₂H₅. 4a was shown by an X-ray structure determination to contain a non-planar ring system.
TL;DR: In this article, the reaction of [H2NPPh2NPh2NH2]Cl (1) with WClft (2) proceeds with formation of (3) and HCl5N6P4Ph8W2 (4).
Abstract: The reaction of [H2NPPh2NPPh2NH2]Cl (1) with WClft (2) proceeds with formation of (3) and HCl5N6P4Ph8W2 (4). 3 is the main product of this reaction. 4 was characterized by an X-ray structure determination. 4 contains a seven and a six-membered phosphorus-nitrogen ring with a W-W bond of 269.2 pm.
TL;DR: The linear phosphazene [H2NPPh2NP Ph2NH2]Cl(1) reacts with MoCl3N and NbCl5 to form the new cyclometallaphosphazenes [graphic omitted]oCl3(3) and bCl2(4), respectively as mentioned in this paper.
Abstract: The linear phosphazene [H2NPPh2NPPh2NH2]Cl(1) reacts with MoCl3N and NbCl5 to form the new cyclometallaphosphazenes [graphic omitted]oCl3(3) and [graphic omitted]bCl2(4), respectively. The crystal structure of the acetonitrile adduct of the cyclomolybdaphosphazene (3) shows that the central six-membered ring is nearly planar.
TL;DR: In this article, a trialkyl phosphite reaction with 2-aklyl-1,3,4,4(2H)-isoquinolinedion-4-ylidene derivatives was shown to yield reduction products with spectral data and X-ray crystallography.
Abstract: Alkoxy-substituted 2-aklyl-1,3,4(2H)-isoquinolinetriones (7) react with trialkyl phosphites to give the corresponding 1,3(2H,4H)-isoquinolinedion-4-ylidene derivatives 8 and trialkyl phosphates. The reaction of 8 with trialkyl phosphites in the presence of water affords reduction products shown to be 1,3(2H,4H)-isoquinolinedion-4-yl derivatives 9 by the spectral data and X-ray crystallography.