Synthesis and structural characterization of titanium complexes containing a sulfinyl-bridged bis(phenolato) ligand

Abstract Titanium complexes containing the novel tridentate 2,2′-sulfinylbis(6-tert-butyl-4-methylphenoxo) ligand (sibmp) were synthesized and characterized. Treatment of titanium tetra-iso-propoxide with 2,2′-sulfinylbis(6-tert-4-methylphenol) (sibmpH2) in 1:1 molar ratio afforded red-orange, sparingly soluble di-iso-propoxo derivative [Ti(sibmp)(O-i-Pr)2]2·0.5 Et2O. The single-crystal structure analysis was performed and revealed a dimeric centrosymmetric structure with a planar Ti2O2 core. The titanium center is approximately octahedral with a SO function intramolecularly coordinated at the titanium center. Treatment of sibmpH2 with titanium tetra-iso-propoxide in 2:1 molar ratio gave y…

Homoleptic Phosphoraneiminato Complexes of Rare Earth Elements as Initiators for Ring-Opening Polymerization of Lactones.

ChemInform Abstract: Carbazole Synthesis via an in situ Trapping Strategy with Indolyl Enol Ethers.

Indolyl enol ethers, generated from the alkoxy(indolyl)carbenium tetra- fluoroborates (1) by treatment with sodium hydride, can be trapped with dimethyl acetylenedicarboxylate or N-phenylmaleimide to furnish the se- lectively functionalized carbazoles (3), (4), (5), (9), (10), and (13). In addition, the biaryl derivatives (6) and (11) are produced by a ring- opening reaction of the primarily formed Diels-Alder adduct. In the case of the biaryl derivative (6), an X-ray crystal structure analysis yields valuable information on constitutions and configurations in the biaryl series. The phenomenon of atropisomerism is discussed for this compound

Organotin(IV) complexes with tetraethyl ethylene- and propylene-diphosphonates

The series of organotin halide complexes with tetraethyl ethylene- and propylene-diphosphonates R n SnX 4-n .L [n=0, X=Cl; n=1, R=Me, X=Cl, Br; n=1, R=Ph, X=Cl; n=2 R=Me, Et, Bu, X=Cl, Br; n=2, R=Ph, X=Cl; L=(EtO) 2 P(O)CH 2 CHR'P(O)(OEt) 2 , R'=H, Me] were synthesized and characterized by means of NMR and Mossbauer spectroscopy. The crystal structure of the complex of diphenyltin dichloride with propylenediphosphonate was determined. The complex consists of polymer chains with bridging bidentate ligands and an octahedral tin environment containing two types of phosphoryl fragments. All of the R 2 SnX 2 adducts have trans-R 2 SnX 4 geometries of tin coordination octahedra according to the q…

Cycloadditions of vinylindoles with chiral carbodienophiles: the first asymmetric Diels-Alder reactions in the vinylhetarane series

Abstract The first asymmetric Diels-Alder reactions of some 3- and 2-vinylindoles with (N-propenoyl)bornane-10,2-sultam are described. With one exception, the experimental results are indicative of a high π-facial diastereoselectivity. Following a related procedure, 3-vinylindoles were also allowed to react with a racemic bis(naphthylsulfonyl)-dienophile to furnish tetrahydrocarbazoles with endo-diastereoselectivity.

Phosphoraneiminato complexes of manganese and cobalt with heterocubane structure

The phosphoraneiminato complexes [MnBr(NPEt3)]4 (1) and [M4Br5{NP(NMe2)3}3] with M = Mn (2) and M = Co (3) are prepared by melting reactions from the anhydrous metal dibromides with the silylated phosphaneimines Me3SiNPR3 (R = Et, NMe2) in the presence of potassium fluoride. All complexes are characterized by crystal structure analyses. 1 forms an only slightly distorted Mn4N4 heterocubane skeleton with an approximate Td symmetry and short Mn…Mn distances of average 295.7 pm. In the structures of 2 and 3 one μ3-NPEt3 ligand of 1 is replaced by one bromine atom with μ3-function. This leads to the novel heterocubane type M4N3Br with approximate C3 symmetry. The deformation of the cubic skelet…

Aluminum complexes of sterically hindered tetradentate Schiff bases: Synthesis, structure, and reactivity toward ɛ-caprolactone

Abstract The sterically hindered Schiff bases tbmSalenH2 [tbmSalen = N,N′-1,2-ethylenebis(3-tert-butyl-5-methylsalicylideneimine)] and tbmSalcenH2 [tbmSalcen = N,N′-trans-1,2-cyclohexanediyl-bis(3-tert-butyl-5-methylsalicylideneimine)] afforded a series of aluminum complexes of the general formulae [Al(tbmSalen)X] and [Al(tbmSalcen)X] (X = Cl, Me, Et). The molecular structure of [Al(tbmSalcen)Cl] was determined by single-crystal X-ray structural analysis which revealed a five-coordinate aluminum center with a distorted square pyramidal geometry. The alkyl complexes were found to oligomerize ɛ-caprolactone.

Synthesis and structural, spectroscopic and magnetic characterization of iron(II) and iron(III) complexes of N-2-pyridinylcarbonyl-2-pyridinecarboximidate

Abstract One iron(II) complex of N -2-pyridinylcarbonyl-2-pyridinecarboximidate monoanion (bpca), [Fe(bpca) 2 ]·H 2 O ( 1 ), and three iron(III) complexes, [Fe(bpca)Cl 2 (H 2 O)]·(CH 3 ) 2 CO ( 2 ), [Fe(bpca) 2 ](NO 3 )·1.67H 2 O ( 3 ), [Fe(bpca) 2 ](ClO 4 ) ( 4 ), have been prepared and characterized by means of IR, UV-Vis and EPR spectroscopy and magnetic susceptibility measurements, where appropriate. The crystal structures of 1 – 3 have been determined from single crystal X-ray data, showing that the metallic ions are surrounded in all cases by distorted octahedral coordination spheres. From magnetic measurements it is evident that compounds 1 and 3 are practically in the low-spin state…

ChemInform Abstract: Diels-Alder Reactions of (1H-Indol-3-yl)-enacetamides and -endiacetamides: A Selective Access to Acetylamino-Functionalized (b)Anellated Indoles and Carbazoles.

Neue Pseudooxokohlenstoff-Dianionen der C4-Reihe

Das vollstandige Manuskript dieser Zuschrift erscheint in: Angew. Chem. Suppl. 1982, 582. DOI: 10.1002/ange.198205820

Homoleptische Phosphaniminato‐Komplexe von Seltenerdelementen als Initiatoren für die ringöffnende Polymerisation von Lactonen

Titanium Complexes of Chelating Bis(phenolato) Ligands with Long Titanium−Sulfur Bonds. A Novel Type of Ancillary Ligand for Olefin Polymerization Catalysts

The sulfide-linked bis(phenol) tbmpH2 (tbmp = 2,2‘-thiobis(6-tert-butyl-4-methylphenolato)) gives a series of titanium complexes of the formula [Ti(tbmp)X2]2 or [Ti(tbmp)(L)X2] (L = two-electron ligand, X = one-electron ligand). The molecular structures of [Ti(tbmp)(OiPr)2]2 and of [Ti(tbmp){C6H4(CH2NMe2)-2}Cl] were determined by single-crystal X-ray structural analyses. An unusually long titanium−sulfur bond of ∼270 pm is observed in both complexes which contain a six-coordinate titanium center. Variable-temperature NMR spectroscopy shows a fluxional coordination of the chelating aryl group in [Ti(tbmp){C6H4(CH2NMe2)-2}Cl].

Carbazole synthesisviaanin situtrapping strategy with indolyl enol ethers

Indolyl enol ethers, generated from the alkoxy(indolyl)carbenium tetra- fluoroborates (1) by treatment with sodium hydride, can be trapped with dimethyl acetylenedicarboxylate or N-phenylmaleimide to furnish the se- lectively functionalized carbazoles (3), (4), (5), (9), (10), and (13). In addition, the biaryl derivatives (6) and (11) are produced by a ring- opening reaction of the primarily formed Diels-Alder adduct. In the case of the biaryl derivative (6), an X-ray crystal structure analysis yields valuable information on constitutions and configurations in the biaryl series. The phenomenon of atropisomerism is discussed for this compound

Alcoholysis of Aluminum Alkyls Supported by Bulky Phenoxide Ligands: Synthesis, Characterization, and ε-Caprolactone Polymerization Activity of Two Dimeric Aluminum Isopropoxides

Reaction of trialkylaluminum Al2R6 (R = Me, Et) with 2,2′-methylenebis(6-tert-butyl-4-methylphenol) (mbmpH2) gives the dimeric mono(alkyl) complex [Al(mbmp)R]2 with bridging oxygen atoms. Reaction of [Al(mbmp)R]2 with one equiv. of 2-propanol results in the formation of the dimeric isopropoxide [Al(mbmp)(μ-OiPr)]2. Single-crystal X-ray analysis shows a C2h-symmetric structure with a planar Al2O2 core. Monomeric methylbis(2,6-di-tert-butyl-4-methylphenolato)aluminum, AlMe(OC6H2-2,6-tBu2-4-Me)2 (MAD), was found to react with one equiv. of 2-propanol to give a dimeric isopropoxide [AlMe(OC6H2-2,6-tBu2-4-Me)(μ-OiPr)]2 in which the bulky phenolate, instead of the methyl group, has been displaced…

Diels-Alder Reactions of (1H-Indol-3-yl)-enacetamides and -endiacetamides: A Selective Access to Acetylamino-Functionalized [b]Annelated Indoles and Carbazoles

Diels-Alder reactions of the (1H-indol-3-yl)-enacetamides and -endiacetamides 1a–d with some carbodieno-philes and 4-phenyl-3H-1,2,4-triazole-3,5(4H)-dione give rise to the novel amino-functionalized carbazole; 4–6 and 8 (Scheme 3). Ethenetetracarbonitrile reacts with 1b to furnish the Michael-type adduct 7 (Scheme 3). Structural aspects of the starting materials 1, which exhibit above all 3-vinyl-1H-indole reactivity, are discussed with regard to the prediction of a Diels-Alder process.

Zur Struktur der Produkte der Reaktion vonE/Z-1-Benzolsulfonyl-3-(1-pentenyl)-indol mit N-Phenylmaleinimid: Ein erster Beitrag zur Konfigurations- und Konformationsanalyse in der Vinylindol-Cycloadditionsreihe

The products2,3 of the reaction ofE/Z-1-benzenesulfonyl-3-(1-pentenyl)-indole (1) and N-phenylmaleimide were analysed by1H-NMR spectroscopy. Exemplarily, the structure elucidation of theendo-cyclo-adduct2 b was achieved by using several NMR techniques (diff. NOE-, INDOR-measurements, decoupling experiments, spectra simulation). The1H-NMR-spectroscopically gained prediction of relative configuration and conformation of2 b was supported on X-ray analysis. The cyclohexene ring of the new cycloadducts adopts in the liquid phase and in the crystal a slightly twisted boat conformation.