Boron-pyrazole chemistry.  II.  Poly(1-pyrazolyl)-borates

Trofimenko, Swiatoslaw

doi:10.1021/ja00989a017

Cited by 564 publications

(331 citation statements)

References 1 publication

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“…43 An allylic rearrangement/oxidation of compound 11 induced by indium chloride and IBX 44 provided the enantiopure allylic acetate (S)-12 45 in 75% yield. Treatment of compound (S)-12 with 1.0 equiv of (toluene)Mo(CO) 3 46 in dichloromethane at room temperature over 4 days, followed by the addition of potassium hydridotris(pyrazolyl) borate (K + TP − ), 47 provided complex (+)-3 in 62% yield with excellent enantiomeric excess (97% ee) via a retention of configuration pathway. 41 The synthesis of racemic lactamyl scaffold (±)-4 has also been dramatically improved compared to the previously described 11-step process.…”

Section: Synthesis Of Lactonyl and Lactamyl Scaffolds 3 Andmentioning

confidence: 99%

Organometallic Enantiomeric Scaffolding: General Access to 2-Substituted Oxa- and Azabicyclo[3.2.1]octenes via a Brønsted Acid Catalyzed [5 + 2] Cycloaddition Reaction

Garnier

Liebeskind

2008

J. Am. Chem. Soc.

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Abstract6-Substituted TpMo(CO) 2 (η-2,3,4-pyranyl)-and TpMo(CO) 2 (η-2,3,4-pyridinyl) scaffolds (Tp = hydridotrispyrazolylborato) function as reaction partners in an efficient regio-and stereocontrolled synthesis of functionalized oxa-and azabicyclo[3.2.1]octenes through a novel Brønsted acidcatalyzed [5+2] cycloaddition reaction. Excellent exo-selectivities are obtained and the reaction gives products with complete retention of enantiomeric purity when carried out with chiral, non-racemic scaffolds. The substituent at C-6 of the η 3 -coordinated heterocyclic scaffold not only influences [5 +2] reactivity but also plays a critical role in the demetalation step directing the reaction to only one of two possible products.

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Section: Synthesis Of Lactonyl and Lactamyl Scaffolds 3 Andmentioning

confidence: 99%

Organometallic Enantiomeric Scaffolding: General Access to 2-Substituted Oxa- and Azabicyclo[3.2.1]octenes via a Brønsted Acid Catalyzed [5 + 2] Cycloaddition Reaction

Garnier

Liebeskind

2008

J. Am. Chem. Soc.

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“…Yield 75%. (2) Good quality crystals of KTm were obtained from an aqueous solution that was left at room temperature for several days. All measurements were made at 120 K on an Enraf-Nonius Kappa-CCD difractometer (95 mm CCD camera on κ-goniostat) with graphite monochromated Mo Kα (λ = 0.71073 Å) radiation.…”

Section: Preparation Of Potassium Hydrotris(2-mercaptothiazolyl)boratmentioning

confidence: 99%

“…For many applications it is easier to handle, more stable and cheaper, than Cp -. 2 The pyrazolyl nitrogen atoms are hard donors and analogues of this proligand bearing softer donor atoms, such as sulfur, are of interest. For example, by following Trofimenko's procedure for the preparation of the Tp -proligand, 2 Reglinski et al demonstrated that reaction of methimazole (2-mercapto-1-methylimidazol) with NaBH 4 yields hydrotris(methimazole)borate, Tm -.…”

Section: Introductionmentioning

confidence: 99%

“…2 The pyrazolyl nitrogen atoms are hard donors and analogues of this proligand bearing softer donor atoms, such as sulfur, are of interest. For example, by following Trofimenko's procedure for the preparation of the Tp -proligand, 2 Reglinski et al demonstrated that reaction of methimazole (2-mercapto-1-methylimidazol) with NaBH 4 yields hydrotris(methimazole)borate, Tm -. 3 A similar but softer proligand, hydrotris(2-mercaptothiazolyl)borate, Mt -, derived from 2-mercaptothiazoline, has also been prepared as the sodium salt.…”

Section: Introductionmentioning

confidence: 99%

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Syntheses, characterization and X-ray structure of potassium hydrotris(2-mercaptothiazolyl)borate, KMt, and potassium hydrotris(methimazole)borate, KTm

Soares

Silva

Ellena

et al. 2004

J. Braz. Chem. Soc.

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Os compostos hidrotris(2-mercaptotiazolil)borato de potássio, KMt, (1), e hidrotris(2-metimazolil)borato de potássio, KTm, (2), foram preparados ao se reagir a amina tiol correspondente com KBH 4 . Foram caracterizados por métodos espectroscópicos e análise elementar. As estruturas no estado sólido de KMt.4H 2 O e do composto 2 foram determinadas por análises de difração de raios-X. A maior maciez do ânion em KMt.4H 2 O, em comparação com 2, é indicada pela ausência de interação entre ele e o cátion, que possui moléculas de água em sua esfera de coordenação. Em KMt.4H 2 O a geometria em torno do íon potássio é octaédrica distorcida e em 2, pirâmide de base quadrada distorcida. Em 2 o íon potássio está coordenado a dois átomos de enxofre dos anéis de um mesmo ânion e a três outros átomos de enxofre pertencentes a unidades KTm vizinhas. Ambos os compostos possuem uma estrutura polimérica.Potassium hydrotris(2-mercaptothiazolyl)borate, KMt, (1) and potassium hydrotris(2-methimazole), KTm, (2), were prepared by reacting the appropriate amine thiol with KBH 4 . They were characterized by spectroscopic methods and elemental analysis. Solid state structures of KMt.4H 2 O and compound 2 were determined by X-ray diffraction analyses. The softer nature of the anion in the former as compared to 2 is indicated by the lack of interaction of the anion with the cation, that has water molecules in its coordination sphere. In KMt.4H 2 O the geometry around the potassium cation is distorted octahedral and in 2, distorted square pyramidal. In 2 the potassium ion is coordinated to two sulfur atoms of one hydrotris(methimazole)borate unit and to other three sulfur atoms belonging to neighboring KTm units. Both compounds have a polymeric structure.

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“…Poly(pyrazolyl)borate ligands were first synthesised by Trofimenko [1]. Hydrotris(3,5-dimethyl-1-pyrazolyl)borate, Tp*, is a facially co-ordinating ligand similar to the 6e oxo complexes, which are of great importance from basic as well as applied points of view.…”

Section: Introductionmentioning

confidence: 99%

Synthesis, spectroscopic characterization and X-ray crystal structures of oxo-bridged oxo(haloaryl) imido hydrotris(3,5-dimethylpyrazolyl)borate molybdenum(V) complexes

Topaloglu-Sozuer

Irdem

Jeffery

et al. 2005

Journal of Coordination Chemistry

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. This is a new synthetic method for preparing Mo-O-Mo bridged oxo(imido) molybdenum(V) species by double deprotonation of the anilines. The complexes were characterized by IR and 1 H-NMR. spectroscopy, FAB mass spectrometry, elemental analysis and X-ray crystallography which revealed that the two chloro ligands are trans to each other in 1b and 2, whereas they are cis to each other in 1a. All compounds have Mo-O-Mo linkages and near linear arylimido moieties.

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Boron-pyrazole chemistry. II. Poly(1-pyrazolyl)-borates

Cited by 564 publications

References 1 publication

Organometallic Enantiomeric Scaffolding: General Access to 2-Substituted Oxa- and Azabicyclo[3.2.1]octenes via a Brønsted Acid Catalyzed [5 + 2] Cycloaddition Reaction

Organometallic Enantiomeric Scaffolding: General Access to 2-Substituted Oxa- and Azabicyclo[3.2.1]octenes via a Brønsted Acid Catalyzed [5 + 2] Cycloaddition Reaction

Syntheses, characterization and X-ray structure of potassium hydrotris(2-mercaptothiazolyl)borate, KMt, and potassium hydrotris(methimazole)borate, KTm

Synthesis, spectroscopic characterization and X-ray crystal structures of oxo-bridged oxo(haloaryl) imido hydrotris(3,5-dimethylpyrazolyl)borate molybdenum(V) complexes

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