Resolution and Stereochemistry of <i>tert</i>-Butylphenylphosphinous Acid−Borane

Stankevič, M.; Pietrusiewicz, K. Michał

doi:10.1021/jo061896e

Cited by 59 publications

(35 citation statements)

References 19 publications

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“…We are at this stage unable to offer an explanation as to how this reduction proceeds. Similar reactions in the literature use metal hydrides [14] or Birch conditions (Li solvated in NH 3 ) [15]. It could be speculated that in our case insertion of the metal center into a C-H bond of the phosphane lig- and could produce a metal hydride, which could then transfer H − to the phosphorus atom, to yield diethylphosphane.…”

Section: Resultssupporting

confidence: 54%

See 1 more Smart Citation

Bond Activation in Iron(II) and Nickel(II) Complexes of Polypodal Phosphanes

Gentschow¹,

Kohl²,

Bauer³

et al. 2010

Zeitschrift Für Naturforschung B

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A pyridine-derived tetraphosphane ligand (donor set: NP 4 ) has been found to undergo remarkably specific C-P bond cleavage reactions, thereby producing a ligand with an NP 3 donor set. The reaction may be reversed under suitable conditions, with regeneration of the original NP 4 ligand. In order to investigate the mechanism of this reaction, the NP 3 donor ligand C 5 H 3 N[CMe(CH 2 PMe 2 ) 2 ][CMe 2 (CH 2 PMe 2 )] (11) was prepared, and its iron(II) complex 4 generated from Fe(BF 4 ) 2 · 6 H 2 O, with methyl diethylphosphinite (7) as an additional monodentate ligand. Ligand 11 has, in addition to the NP 3 donor set, one methyl group in close contact with the iron center, reminiscent of an agostic M···H-C interaction. Depending on the stoichiometric amount of iron(II) salt, a side product 15 is formed, which has a diethylphosphane ligand instead of the phosphinite 7 coordinated to iron(II). While attempts to deprotonate the metal-coordinated methyl group in 4 were unsuccessful, the reaction was shown to occur in an alternative complex (18), which is similar to 4 but has a trimethylphosphane ligand instead of the phosphinite 7. The reaction of complex 15 with CO gave two different products, which were both characterized by single-crystal X-ray diffraction. One (19) is the dicarbonyl iron(II) complex of the triphosphane ligand 11, the other (3) is the carbonyl iron(II) complex of the tetraphosphane C 5 H 3 N[CMe(CH 2 PMe 2 ) 2 ] 2 (1). This suggests an intermolecular mechanism for the C-P bond formation in question.

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Section: Resultssupporting

confidence: 54%

“…It was dried in vacuo to give a colorless powder (14.1 g, 0.134 mol, 83 %). (15) The procedure was the same as for the preparation of 4, except that 0.5 eq. of Fe(BF 4 ) 2 · 6 H 2 O was used instead of 0.1 eq.…”

Section: Lithium Dimethylphosphide (14)mentioning

confidence: 99%

Bond Activation in Iron(II) and Nickel(II) Complexes of Polypodal Phosphanes

Gentschow¹,

Kohl²,

Bauer³

et al. 2010

Zeitschrift Für Naturforschung B

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“…Outras halogenações com compostos contendo -CX 3 , como, por exemplo, organosfosforados, incluindo reações estereosseletivas, 98,99 enaminas 100 e anéis aromáticos são encontradas na literatura. 101 Recentemente foi mostrado que a aziridina N-tosilada 63, derivada do cicloexano, reage com CCTHs (HCA, ácido tricloroacético ou tricloroacetamida), em PPh 3 , para formar a α-cloroamina N-tosilada 64, por abertura do anel aziridínico, com ótimos rendimentos (87 a 97%) em condições brandas (Esquema 20).…”

Section: Outras Halogenações Mediadas Por Ccthsunclassified

Recentes aplicações sintéticas de compostos orgânicos tricloro(bromo)metila substituídos

Menezes¹,

Gallardo²,

Zucco³

2010

Quím. Nova

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Recebido em 1/7/10; aceito em 11/10/10; publicado na web em 16/11/10 RECENT SYNTHETIC APPLICATIONS OF TRICHLORO(BROMO)METHYL CONTAINING ORGANIC COMPOUNDS. This review presents the recent applications of some trihalomethyl carbinols, α,α,α-trihalogenated carbonyl compounds and trichloro(bromo)methyl-containing heterocycles, acting as high versatile synthetic precursors in organic chemistry, based on the last 10 years' literature.Keywords: trichloro(bromo)methyl compounds; synthetic applications. INTRODUÇÃO O grupo tricloro(bromo)metilaCompostos orgânicos contendo grupos -CCl 3 ou -CBr 3 em suas estruturas possuem diversas aplicações em diferentes áreas como bioquímica, agroquímica, produtos naturais, mas são reconhecidos, sobretudo, como reagentes altamente versáteis em síntese orgânica. O clorofórmio, por exemplo, o derivado mais simples contendo o grupo -CCl 3 , é um solvente de larga utilização em laboratórios. A Figura 1 mostra alguns compostos contendo o grupo -CX 3 , dotados de interessantes propriedades. O DDT, 1, é o inseticida mais conhecido da história.1 O composto piridínico 2 é relatado como um agente antitumoral 2 e o derivado arsênico 3 possui atividade antileucêmica.3 O grupo -CCl 3 é fundamental para a atividade biológica do Salubrinal, 4, uma molécula altamente eficaz na proteção de células sadias contra apoptose induzida por estresse excessivo e incorreto do retículo endoplasmático, fato responsável por importantes patologias como diabetes, Alzheimer e infecções virais. 4,5 Com relação aos derivados contendo o grupo -CBr 3 , destaca-se o agente neurotóxico 5.6 Já o composto 6 é um dos componentes da alga vermelha Asparagopsis Taxiformis, que apresenta atividade contra aldose redutase em bovinos. 7 Aplicações sintéticas de compostos orgânicos contendo -CX 3O desenvolvimento de novas estratégias e metodologias em sín-tese orgânica é um acontecimento recorrente e promissor de pesquisa em Química, e, nesse contexto, compostos orgânicos contendo o grupo -CX 3 (X = Cl, Br) têm sido citados na literatura como reagentes úteis e versáteis em diversas circuntâncias. Nesta revisão, serão apresentados exemplos relatados, principalmente na última década, envolvendo a utilização de tri-halometil carbinois (THMCs), compostos carbonilados α,α,α-tri-halogenados (CCTHs) e heterociclos contendo -CX 3 como precursores sintéticos de funções químicas variadas. Esses compostos atuam, muitas vezes, como peças fundamentais em estratégias de síntese de moléculas altamente elaboradas e de acentuada importância.Em 1934, Fuson e Bull publicaram um artigo de revisão acerca da reação do halofórmio, apontando, já naquela época, utilização dessa reação em análises qualitativas e quantitativas, suas aplicações em síntese e explicações mecanísticas. 8 De fato, a reação do halofórmio é uma das mais antigas na Química. Em 1822, Serulla, acidentalmente, verificou que o tratamento de etanol com hipoiodito, formado a partir de iodo em solução básica de hidróxido, levava à obtenção de iodofórmio e íon formato, por reação de oxidação do...

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“…(S)-tert-Butylmethylphenylphosphine-borane (3e), [1][2][3][4] (S)-tert-Butyl(o-methoxyphenyl)-methylphosphine-borane (3f), [2,5] and (S)-Benzyl(tert-butyl)methylphosphine-borane (4b) [6,7] The absolute configurations and enantiomeric excesses of the products (3e, 3f, and 4b) were determined by HPLC analysis in comparison with the reported data. [1][2][3][4][5][6][7] 3e: Daicel Chiralcel OJ-H, Hexane/iPrOH = 9/1, Flow rate = 0.5 mL/min, UV = 230 nm, t R = 25.5 min (R), t R = 27.7 min (S); 3f: Daicel Chiralcel OD-H, Hexane/iPrOH = 99/1, Flow rate = 0.5 mL/min, UV = 230 nm, t R = 11.0 min (R), t R = 11.6 min (S); 4b: Daicel Chiralcel OD-H, Hexane/iPrOH = 9/1, Flow rate = 0.5 mL/min, UV = 230 nm, t R = 16.9 min (R), t R = 18.9 min (S).…”

mentioning

confidence: 99%

“…[1][2][3][4][5][6][7] 3e: Daicel Chiralcel OJ-H, Hexane/iPrOH = 9/1, Flow rate = 0.5 mL/min, UV = 230 nm, t R = 25.5 min (R), t R = 27.7 min (S); 3f: Daicel Chiralcel OD-H, Hexane/iPrOH = 99/1, Flow rate = 0.5 mL/min, UV = 230 nm, t R = 11.0 min (R), t R = 11.6 min (S); 4b: Daicel Chiralcel OD-H, Hexane/iPrOH = 9/1, Flow rate = 0.5 mL/min, UV = 230 nm, t R = 16.9 min (R), t R = 18.9 min (S). (S,S)-1,2-Bis(boranato(tert-butyl)(phenylethynyl)phosphino)ethane (6a) To a solution of (S)-tert-butylmethyl(phenylethynyl)-phosphine-borane (3a) (97% ee, 0.95 g, 4.4 mmol) and TMEDA (0.8 mL, 5.2 mmol) in dry Et 2 O (13 mL) was added s-BuLi (5.2 mL of a 1.0 M solution in hexane, 5.2 mmol) at -78 °C under nitrogen, and the mixture was stirred for 1 h and -50 °C for 10 min.…”

mentioning

confidence: 99%

Synthesis and Enantioselectivity of P‐Chiral Phosphine Ligands with Alkynyl Groups

et al. 2007

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General.All solvents used in reactions were dried and purified according to standard procedure. NMR spectra were measured with JEOL JMN-GXS-500 (500 MHz) or JEOR JMN-LA-400 (400 MHz) spectrometer in CDCl 3 . Chemical shifts were reported in δ ppm. Optical rotationswere measured with JASCO DIP-370 polarimeter. Enantiomeric excesses were determined by HPLC analysis using Chiralcel AD, OJ-H, OD-H, OB, IA columns and varying concentrations of 2-propanol/hexane as the mobile phase. X-ray crystal structure data were collected using a Bruker SMART APEX II diffractmeter with Mo-Kα radiation. Silica gel (Kanto Chemical, Silica Gel 60N for flash chromatography) was used for column chromatography. (S)-tert-Butylmethyl(phenylethynyl)phosphine-borane (3a)To a solution of (S)-tert-butylmethylphosphine-borane (1) (>99% ee, 1.8 g, 15.4 mmol) in dry Et 2 O (60 mL) was added nBuLi (11.6 mL of a 1.60 M solution in hexane, 18.5 mmol) at -78 °C under nitrogen, and the mixture was stirred for 15 min. 1,2-Dibromoethane (2.0 mL, 23.1 mmol) was added dropwise, and the reaction mixture was stirred at -78 °C. After 2 h, lithium phenylacetylide (30.8 mmol, 30 mL of Et 2 O solution) was added to the reaction mixture, and the mixture was stirred at room temperature. After 1.5 h, the reaction was quenched with 1 M HCl. The mixture was extracted with EtOAc three times. The combined organic layers were washed with saturated NaHCO 3 and brine, and dried over Na 2 SO 4 . After filtration, the filtrate was concentrated under reduced pressure, and the residue was purified by chromatography on silica gel (hexane/EtOAc = 5/1) to give (S)-tert-butylmethyl(phenylethynyl)phosphine-borane (3a) (97% ee, 2.8 g, 12.8 mmol, 83%) as white solid.

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Resolution and Stereochemistry of tert-Butylphenylphosphinous Acid−Borane

Cited by 59 publications

References 19 publications

Bond Activation in Iron(II) and Nickel(II) Complexes of Polypodal Phosphanes

Bond Activation in Iron(II) and Nickel(II) Complexes of Polypodal Phosphanes

Recentes aplicações sintéticas de compostos orgânicos tricloro(bromo)metila substituídos

Synthesis and Enantioselectivity of P‐Chiral Phosphine Ligands with Alkynyl Groups

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