Synthesis of new titanatranes containing organic substituents in the atrane fragment

Abstract

Titanatrane CpTi(OCH(CH 3 )CH 2 ) 3 N (3) was prepared by the reaction of CpTiCl 3 with N(CH 2 CH(CH 3 )OH) 3 in the presence of triethylamine. The reaction of CpTi(OMe) 3 (8) with N(CH 2 CH 2 OH) 2 (CH 2 CHPhOH), erythro N(CH 2 CH 2 OH) 2 (CHPhCHPhOH), and N(CH 2 CH 2 OH) 2 (CH 2 CPh 2 OH) gave cyclopentadienyltitanatranes 12-14. Compound 8 reacts with threo N(CH 2 CH 2 OH) 2 (CHPhCHPhOH) to give a mixture of threo CpTi(OCH 2 CH 2 ) 2 (OCHPhCHPh)N and threo MeOTi(OCH 2 CH 2 ) 2 (OCHPhCHPh)N. Slow hydrolysis of the latter product gave threo [Ti 3 O(OMe){(OCH 2 CH 2 ) 2 (OCHPhCHPh)N} 3 ] 2 , which was studied by X ray diffraction analysis. The crystal structures of 3 and 12 were also determined by X ray diffraction analysis. The titanium coordination polyhedron in these complexes is a distorted trigonal bipyramid in which the equatorial posi tions are occupied by three oxygen atoms and the axial positions contain the N atom and the Cp group. The titanium-nitrogen distances (2.313(2), 2.291(2) Å in two independent mol ecules of 3 and 2.271(2) Å in compound 12) confirm the presence of Ti←N transannular interaction.The chemistry of metallatranes, cyclic ethers of trialkanolamines, has been vigorously developing during the last fifty years. Derivatives of most of chemical ele ments have now been synthesized. The interest in these unusual compounds is due to the possible formation of an intramolecular coordination bond, which changes sub stantially the structure and properties of metallatranes compared to the structures and properties of their close analogs, tris alkoxides in which this type of intramolecu lar interaction is missing. In particular, well known is a higher stability of metallatranes against hydrolysis. There fore, metallatranes may prove more promising from the applied standpoint 1 compared to other metal compounds.The compounds of main group elements, especially silatranes and germatranes, possessing a broad spectrum of biological activities, have been studied in most de tail. 2,3 Transition metal compounds have been much less studied, 4-6 although they could find a broad application, for example, as catalysts for various organic reactions. It is of interest to compare the structures and properties of transition metal atranes with those of the related com pounds formed by nontransition elements; this may pro vide additional information on the nature of the ele ment-nitrogen transannular bond in this type of com pound.In this paper we consider titanatranes, which are struc tural analogs of well studied silatranes and germatranes. Although the first representatives of titanatranes were syn thesized back in the 1960s, 7-9 and in recent decade, the interest in these derivatives has increased, 10-14 at most 20 publications on this topic are known. The attention was focused on the specific features of the structure 15-17 and catalytic properties of chiral trialkanolamine com plexes in the polymerization of olefins and lactide 18-20 and oxidation of sulfides. 21-25 A broad range of titan atranes containing var...

Synthesis of Titanium-Containing Block, Random, End-Functionalized, and Junction-Functionalized Polymers via Ruthenium-Catalyzed Living Radical Polymerization and Direct Observation of Titanium Domains by Electron Microscopy

“…A series of characteristic peaks appeared after reaction with TiCpCl 3 or TiCp*Cl 3 (denoted from f″ to j″ in Figures C,D). These peaks were assigned to discrete titanatrane structures, which are relatively stable titanium complexes that have been used as catalysts and in hybridization reactions with inorganic compounds. − The observed peak area ratios were close to the calculated values for titanatrane structures [ f″ : g″ : h″ : i″ : j″ /2 = 2.0:1:2.0:4.2:2.0 (for Cp), 2.0:1:2.0:4.1:2.2 (for Cp*), and 2:1:2:4:2 (calculated)]. These results clearly indicate that well-defined titanium-containing units were constructed in the copolymers.…”

Titanium (IV) complexes based on substituted 2-[(2-hydroxyethyl)]aminophenols

“…In continuation of our studies of Ti(IV) complexes with tri-and dialkanolamines [12][13][14], we present the synthesis and characterization of titanium complexes (6-9) -titano-spiro-bis(ocanes) -based on the new hybrid tridentate alkanolaminophenol ligands. Their structure in solution is discussed basing on NMR spectroscopy data.…”