Tin(IV) complexes of tridentate schiff bases having ONS donor systems

Synthesis, characterization and in vitro cytotoxicity of new organotin(IV) derivatives of N-methylglycine

Boron complexes of some oxygen-nitrogen and sulphur-nitrogen containing chelating agents

Die zwei 4,5-Diethyl-2,5-dihydro-2,2-dimethyl-3-organo-1,2,5-oxasilaborole werden aus und Wasser uber die Additionsverbindungen [MeNH2-2a (Rontgenstrukturanalyse); MeNH2-2b] in Ausbeuten von ca. 90% hergestellt. 2a, b erhalt man auch unmittelbar aus 1a, b mit Acetylaceton oder mit Eisessig. 1b ist aus Natrium-triethylhydroborat (A) uber Natirum-triethyl(3-methyl-3-buten-1-inyl)-borat (B), (Z)-4-(Diethylboryl)-2-methyl-3-(trimethylsily)-1,3-hexadien (C), Natrium-aminodiethyl[2-methyl-3-(trimethylsilyl)-1,3-hexadien-4-yl]borat (D), 4,5,5-Triethyl-2,5-dihydro-3-isopropenyl-2,2-dimethyl-1-natrio-1,2,5-azoniasilaboratol (E) und 4,5-Diethyl-2,5-dihydro-3-isopropenyl-2,2-dimethyl-1-natrio-1,2,5-azoasilaborol (F) praparativ zuganglich. Das Verhalten von 2a, b gegenuber Trimethylphosphan (TMP), γ-Picolin (Bildung von γ-Pic-2a), γ-Picolin-N-oxid (PNO-2a), Trimethylamin-N-oxid (2′a, 4, 4′a), Methylentriphenylphosphoran (MTPP-2a), Aluminiumtrichlorid (2a-AlCl3), Triethylaluminium [(8a)2], Trichlorboran (3a), Dichlorethylboran (3b), Phosphorpentachlorid (3a, 3b), Methanol (6a), Acetylaceton (5a), Propanol (7a, 7c) und gegenuber Eisessig (7a, 9) wird beschrieben. Aus 1a last sich mit Dichlorethylboran leicht 5-Chlor-4-ethyl-2,5-dihydro-1,2,2,3-tetramethyl-1,2,5-azasilaborol (1c) gewinnen. η4-Komplexierungen von 2b fuhren mit (CH3CN)3Cr(CO)3 zu 10b, mit Fe2(CO)9 zu 11b und 11′b, mit Ru3(CO)12 zu 12b, mit C5H5Co(C2H4)2 zu 13b und mit C5H5Rh(C2H4)2 zu 14b (MS- und NMR-Daten). Der Sauerstoffaustausch wird bei einigen Reaktionen mit Hilfe 17O-angereicherter Verbindungen (z. B. 2a*, Triethylboroxin*, Tetraethyldiboroxan*, Wasser*, Methanol*) 17O-NMR-spektroskopisch verfolgt.



Substituted 2,5-Dihydro-1,2,5-oxasilaboroles — Preparation, Complexations, and Ring-Opening



The two 4,5-Diethyl-2,5-dihydro-2,2-dimethyl-3-organo-1,2,5-oxasilaborole are prepared from and water via the addition compounds [MeNH2-2a (X-ray analysis); MeNH2-2b] in yields of about 90%. 2a, b are also obtained directly from 1a, b with acetylacetone or with dry acetic acid. 1b can be prepared from sodium triethylhydroborate (A) via sodium triethyl(3-buten-1-ynyl)-borate (B), (Z-4-(diethylboryl)-2-methyl-3-(trimethylsily)-1,3-hexadiene (C), sodium aminodiethyl[2-methyl-3-(trimethylsilyl)-1,3-hexadien-4-yl]borate (D), 4,5,5-triethyl-2,5-dihydro-3-isopropenyl-2,2-dimethyl-1-sodio-1,2,5-azoniasilaboratole (E) and 4,5-diethyl-2,5-dihydro-3-isopropenyl-2,2-dimethyl-1-sodio-1,2,5-azasilaborole (F). The behaviour of 2a, b towards trimethylphosphane (TMP), γ-picoline (formation of γ-Pic-2a), γ-picoline N-oxide (PNO-2a), trimethylamine N-oxide (2′a, 4, 4′a), methylene-triphenylphosphorane (MTPP-2a), aluminium trichloride (2a-AlCl3), triethylaluminium [(8a)2], trichloroborane (3a), dichloroethylborane (3a), phosphorus pentachloride (3a, 3b), methanol (6a), acetylacetone (5a), propanol (7a, 7c) and towards glacial acetic acid (7a, 9) is described. 5-Chloro-4-ethyl-2,5-dihydro-1,2,2,3-tetramethyl-1,2,5-azasilaborole (1c) is readily obtainable from 1a and dichloroethylborane. η4-Complexations of 2b give 10b, from (CH3CN)3Cr(CO)311b and 11′b from Fe2(CO)9, 12b from Ru3(CO)12, 13b from C5H5Co(C2H4)2, and 14b from C5H5Rh(C2H4)2 (MS and NMR data). The O-exchange in several reactions was monitored by 17O NMR using 17O-enriched compounds (e.g. 2a*, triethylboroxin*, tetraethyldiboroxane*, water*, methanol*).

Substituierte 2,5‐Dihydro‐1,2,5‐oxasilaborole — Herstellung, Komplexierungen und Ringöffnung

Publisher Summary This chapter presents the Fluorine-19 Nuclear Magnetic Resonance Spectroscopy data present in the literature between January 1979 and the end of June 1981. The major part of this chapter consists of tables containing chemical shift and spin-spin coupling constant information for compounds in the liquid state or in solution. The remaining part covers studies in solids and liquid crystals, together with biological applications and theoretical studies involving F-19 NMR. The tables are arranged according to the type of carbon (or element) to which the fluorine nucleus is bound. The appearance of a compound, with more than one type of fluorine-bonded carbon, in a particular table is according to which fluorine has its chemical shift reported and/or comes higher in the list of tables. Similarly where only coupling constant information is reported the same priority exists. Chemical shift information takes priority over coupling constant information. The only exception is where an attempt has been made to include all the data for carbonium ions and carbanions irrespective of whether fluorine is directly attached to the charged carbon or not. Most of the table consists of (a) the molecular formula of the compound, (b) the structure of the compound, (c) the F-19 chemical shift data, (d) the F-19 spin-spin coupling constant data, and (e) the literature reference number with the reference compound index, given in parentheses, where applicable. Each table is arranged according to the index of the molecular formulae, and the convention adopted for priority of the elements is C, F, H, and then the other elements in alphabetical order.

Fluorine-19 Nuclear Magnetic Resonance Spectroscopy (1979–1981)

Synthesis of B(OEt)(SB) and B(SB)(SBH) types of derivatives (where SB− and SBH− are the anions of the Schiff bases, SBH2) is reported. These are formed by 1:1 and 1:2 molar reactions of boron ethoxide with the bifunctional tridentate Schiff bases such as 3-(2-hydroxyethyl)amino-1-phenyl-2-buten-1-one, 3-(2-hydroxy-n-propyl)amino-1-phenyl-2-buten-1-one and 3-(2-hydroxyphenyl)amino-1-phenyl-2-buten-1-one respectively. The labile nature of the ethoxy groups in 1:1 derivatives has been shown by carrying out exchange reactions with an excess of t-butyl alcohol. The resulting derivatives have been characterized by elemental analysis, molecular weight determinations, conductance measurements and infrared and proton magnetic resonance spectra.

Schiff Base Derivatives of Boron. Synthesis of Boron Derivatives of the Schiff Bases Derived from the Condensation of 1-Phenyl-1,3-butane-dione with Hydroxy Alkylamines or Arylamines

Synthesis of Sn(OAc)4-2n(AZ)n and SnCl4.nAZH2 (where n = 1, 2 and AZ represents the anion of salicylaldazine (SAZH2), o-hydroxy naphthalaldazine (HNAZH2) and o-hydroxy acetophenazine (HAAZH2) type of derivatives is reported. As evidenced by electronic, infrared and proton magnetic resonance spectral studies, these ligands show tridentate behaviour in the resulting complexes. Further, the replacement reactions of acetoxy tin(IV) derivatives with 1, 2-dihydroxy-benzene have resulted in the formation of pentacoordi-nated mixed ligand complexes.

Synthesis and Characterization of Tin(iv) Complexes of Azines

Tetra-coordinated diacetoxy-boron Schiff base derivatives of the type (AcO)2B(SB) (where SB− is the anion of the corresponding monofunctional bidentate Schiff base, SBH) have been synthesized in almost quantitative yields and in a state of sufficient purity by the equimolar ratio reactions of boric acid and Schiff bases in acetic anhydride medium. Even on mixing the reactants in higher molar ratio only 1:1 derivatives could be isolated. On the basis of elemental analyses, molecular weight determinations and conductance measurements and infrared and proton magnetic resonance spectra, the possible structures for the resulting new derivatives have been indicated.

Schiff Base Complexes of Boron: Boron Complexes of Schiff Bases of 2,4-Pentanedione

Reactions of equimolar amounts of BF3.2AcOH with azines have resulted in the synthesis of FB(AZ) (where AZ−2 represents the anion of the azine, AZH2) type of derivatives. Similar reactions of boric acid dissolved in acetic anhydride or of B(OEt)3 with such ligands have produced XB(AZ) (where X = OAc or OEt) type of compounds. Spectral assignments and the mode of bonding have been discussed on the basis of electronic, I.R. and 1H NMR spectral studies. The splitting of √ C=N (∼ 1620 cm−1) and√N-N (1000–900 cm−1) absorptions, each into two bands, indicates the coordination of only one of the two azomethine nitrogens of the ligand to the boron atom. This is further supported by the splitting of the methyl proton signal (2.72 8) of o-hydroxyacetophenoneazine into two signals on chelation with the boron atom. Further, the fluoroboronazinates have been characterized by 19F N.M.R. spectra and all the complexes were found to be monomers in freezing dioxane.

Synthesis and Characterization of Azine Derivatives of Boron

The 1:1 and 1:2 molar ratio reactions of oxybis(diacetoxyborane) with 3-(hydroxyalkyl or aryl)amino-1-phenyl-2-butene-1-one (I) of the general formula C6H5COCHC(CH3):NHR′OH (where R′ = -CH2CH2−, -CH2HCH3 and -C6H4−) in dry toluene have led to the formation of LB-O-B(OAC)2 and (LB)2O type of compounds (where L−2 represents the anion of ligand I)’. Further, equimolar reactions of LB-O-B(OAC)2 with 1,2-dihydroxybenzene or 2-methylpentane-2, 4-diol have resulted in the isolation of mixed ligand complexes of boron. IR and 1H nmr studies indicate the presence of N→B bonds and molecular weight determinations show these compounds to be monomers in boiling chloroform.

H. B. Singh

Papers

Schiff Base Derivatives of Boron. Synthesis of Boron Derivatives of the Schiff Bases Derived from the Condensation of 1-Phenyl-1,3-butane-dione with Hydroxy Alkylamines or Arylamines

Synthesis and Characterization of Tin(iv) Complexes of Azines

Schiff Base Complexes of Boron: Boron Complexes of Schiff Bases of 2,4-Pentanedione

Synthesis and Characterization of Azine Derivatives of Boron

Binuclear Boron Complexes Containing Boron-Nitrogen Bonds