The asymmetric bis-imido structure and the lability of the diethyl ether linkage in complex 1 provide a niobium complex that undergoes regioselective [4+2] cycloaddition reactions with an α,β-unsaturated ketone and cycloaddition reactions that involve bond formation to the MAD ligand (MonoAzabutaDiene). DFT calculations have been used to support an initial azametallacyclobutene intermediate in ...

New crown ether Schiff base derivatives were prepared by the condensation of 4'-formylbenzo-15-crown-5 or 4'-formyl-5'-hydroxybenzo-15-crown-5 with 1,2-bis(2-aminophenoxy)ethane. The structures of these new compounds were confirmed on the basis of elemental analysis, IR, (1)H- and (13)C-NMR, UV-Vis and mass spectroscopic data.

Two new antibiotic metabolites, dacrymenone (1) and VM 3298-2 (2), were isolated from fermentations of a Dacrymyces sp., and their structures were determined by spectroscopic techniques. Dacrymenone (1) is a new eremophilane sesquiterpenoid while VM 3298-2 (2) is a bis-enol ether between methyl pyruvate and 4,6-dihydroxycyclohexan-1,3-dione. Dacrymenone (1) shows weak antibacterial and antifung...

Detailed exuminution of the temperutLtre dependence of the n.m.r. spectra of 3,3-dimeth;,-lbut.,-lmagnesium chloride and bis(3,3-dimethvlbutyl)magnesium indicates that inversiott of configuration at the-CHzMg center oc' curs rapidly in ether solution at room temperature. Activation parameters for the inversiott reactiotts ure E,, : ]l t 2 kcal.f rnole, A : l}c'a = t'5 sec.-t, ond

The title compound, C(25)H(28)N(2)O(5), is a product of the Petrenko-Kritchenko condensation of N-acetyl-piperidone with 1,5-bis-(2-formyl-phen-oxy)-3-oxapentane and ammonium acetate. The mol-ecule comprises a fused penta-cyclic system containing an aza-14-crown-3-ether macrocycle, two piperidone and two benzene rings. The aza-14-crown-3-ether ring adopts a bowl conformation. The dihedral angle...

Treatment of the pentamethylcyclopentadienylruthenium chloride tetramer [Cp*RuCl]4 with bis(dimethylphosphino)methane (dmpm) in tetrahydrofuran affords three ruthenium(II) phosphine complexes, Cp*Ru(dmpm)Cl, [Cp*Ru(dmpm)(η1-dmpm)]Cl, and Cp*2Ru2(μ-dmpm)2Cl2. Similar treatment of [Cp*RuCl]4 with bis(diphenylphosphino)methane (dppm) in tetrahydrofuran or diethyl ether affords the dinuclear specie...

A series of amine functionalized ligands, including 2,2'-(benzylazanediyl)bis(N,N'-dimethylacetamide) (BnABDMA), 2,2'-azanediylbis(N,N'-dimethylacetamide) (ABDMA), and 2,2'-(methylazanediyl)bis(N,N'-dimethylacetamide) (MABDMA), are synthesized for the thermodynamic study of their complexation with Nd(3+) ions. Their complexation in solution is investigated using potentiometry, spectrophotometry...

Pseudorotaxanes from self-assembly of two crown ether-based cryptand wheels and a 1,2-bis(pyridinium) ethane derivative axle were prepared.

Geminal dimetalated amines, phosphanes, and arsanes gained increasing attention due to the expectation of a high reactivity and unique solid-state structures. Power et al.1 reported the molecular structure of a hexameric ether complex of a magnesium imide. The aryl substituent at the nitrogen atom has been a phenyl1 or a naphthyl group.2 Furthermore, the high reactivity allows the synthesis of ...

New fluorovinylene aromatic ether polymers, possessing dual reactivity, have been successfully prepared via the step-growth polymerization of commercial bis(trifluorovinyl) aromatic ethers and bisphenols.