Carbodiimides. III. Conversion of Isocyanates to Carbodiimides. Catalyst Studies

Monagle, John J.

doi:10.1021/jo01058a022

Cited by 111 publications

(32 citation statements)

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“…Hydroxyl-terminated PDMS (M n ¼ 15,000 g/mol), tetraethyl orthosilicate (TEOS) and stannous-2-ethyl-hexanoate (SNB1100) were obtained from Gelest Inc. APTES and N, N 0 -diisopropylcarbodiimide (DIC) were obtained from Aldrich Company, Inc. and chloroform was purchased from the Tedia Company, Inc. GO was prepared according to the modified Hummers Method [2,39] Preparation of A-GO. APTES-modified GO (A-GO) was made using the reaction between carboxylic acid groups and amino groups (using DIC to activate amino groups) [40], as shown in Scheme 1. This synthesis was carried out at 70 C for 4 hanhydrously under nitrogen to prevent the hydrolysis of the alkoxyl groups in the silane [41].…”

Section: Methodsmentioning

confidence: 99%

What factors control the mechanical properties of poly (dimethylsiloxane) reinforced with nanosheets of 3-aminopropyltriethoxysilane modified graphene oxide?

Zhang

Zhu

Gui

et al. 2013

Polymer

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Section: Methodsmentioning

confidence: 99%

What factors control the mechanical properties of poly (dimethylsiloxane) reinforced with nanosheets of 3-aminopropyltriethoxysilane modified graphene oxide?

Zhang

Zhu

Gui

et al. 2013

Polymer

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“…The standard flash chromatographic purification with hexanes was carried out to isolate the analogous six-membered arsine (deoxo)-14, (entry 3), however the product was found to be contaminated with non-volatile hydrocarbons derived from Grignard hydrolysis and Wurtz-coupling processes. Thus, subsequent treatment with H 2 O 2 [15] was performed to isolate the more polar oxide derivative 14 in an overall 26% yield. It should be noted that desymmetrized heterocycles 12−14 have been obtained as racemic mixtures due to the newly installed arsenic stereocentre.…”

Section: Resultsmentioning

confidence: 99%

“…Selected compounds were nonetheless readily converted to their As(V) analogues by oxidation with H 2 O 2 [15] (Scheme 4). No As−C(sp a Previously reported in 96% yield but was not fully characterized [15].…”

Section: Resultsmentioning

confidence: 99%

“…FTIR: v 3320, 2925, 2317, 1700, 1653, 1507, 1044, 668 cm Synthesis of 1-(Naphthalen-1-yl)arsolane (19) A suspension of Mg (223 mg, 9.17 mmol) and 1,4-dibromobutane (990 mg, 4.59 mmol) in THF (5 mL) was stirred at rt for 1 h. The resulting dark grey solution was added dropwise to a solution of (1-naphthylAsO) x (200 mg, 0.92 mmol) in THF (9 mL) at −78 °C and the mixture was allowed to warm to rt and stirred for 20 h. Water (20 mL) was slowly added and the mixture was extracted with EtOAc (2×20 mL). The combined extracts were washed with brine (20 Synthesis of 1-Phenylarsolane-1-oxide (20) Based on a literature procedure [15], to a solution of 10 (700 mg, 3.36 mmol) in acetone (10 mL) was added H 2 O 2 (30% aqueous, 573 mg total, 5.05 mmol H 2 O 2 ) and the solution was stirred at rt for 12 h. The solution was concentrated under reduced pressure and the residue subjected to column chromatography (EtOAc to 20% NEt 3 /EtOAc) to afford 20 [15] …”

Section: Synthesis Of 1-bromo-2-(2-chloroethyl)naphthalene (Novel Prementioning

confidence: 99%

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Arsenous chloride-free synthesis of cyclic tertiary organoarsines from arylarsine oxides and di-Grignard reagents

Gregson

Wales

Bailey

et al. 2015

Journal of Organometallic Chemistry

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. (2015). Arsenous chloride-free synthesis of cyclic tertiary organoarsines from arylarsine oxides and di-Grignard reagents. Journal of Organometallic Chemistry, 785 77-83.Arsenous chloride-free synthesis of cyclic tertiary organoarsines from arylarsine oxides and di-Grignard reagents AbstractThe growing importance of triarylarsines as ligands for transition metal catalysis has sparked recent interest in new synthetic routes to tertiary arsines that avoid hazardous arsenous chloride reagents. However, safer methods for the synthesis of lesser explored arsine heterocycles, especially those containing As-C(sp3) bonds, remain lacking. We demonstrate for the first time that bench stable, less hazardous, arylarsine(III) oxides are effective substitutes for their corresponding chlorides in the one-pot construction of cyclic tertiary organoarsines from di-Grignard reagents. Several known and novel heterocycles have been prepared in reasonable yields, accommodating variations in both the diorganomagnesium reagent and electrophile, making this a modular approach to cyclic arsine assembly. Graphical Abstract AbstractThe growing importance of triarylarsines as ligands for transition metal catalysis has sparked recent interest in new synthetic routes to tertiary arsines that avoid hazardous arsenous chloride reagents. However, safer methods for the synthesis of lesser explored arsine heterocycles, especially those containing As−C(sp 3 ) bonds, remain lacking. We demonstrate for the first time that bench stable, less hazardous, arylarsine(III) oxides are effective substitutes for their corresponding chlorides in the one-pot construction of cyclic tertiary organoarsines from di-Grignard reagents. Several known and novel heterocycles have been prepared in reasonable yields, accommodating variations in both the diorganomagnesium reagent and electrophile, making this a modular approach to cyclic arsine assembly. Keywords: Arsine oxides, Grignard reagents, Heterocycles, Organoarsines, Ligands IntroductionOrganoarsines have found application in coordination chemistry [1], materials science [2] and recently in chemotherapy as potential drug delivery and anti-cancer agents [3]. Triaryl arsines in particular are now well established as valuable ligands for transition metal catalysis, demonstrating superiority to analogous phosphines in many cases [4]. Although tertiary organoarsines are traditionally prepared via the combination of arsenic chlorides (or other halides) with organometallic reagents or nucleophilic arenes, a major drawback to this approach is the inherent toxicity associated with the As−Cl bond [5]. It is well known that arsenic compounds (or metabolites thereof) generally exhibit toxicity [6], however, most arsenous chlorides are additionally characterized by alarming acute effects based on their rapid in vivo covalent binding to thiol-containing enzymes and proteins [7]. These hazards are exacerbated by the often semi-volatility of arsenous(III) chlorides, which have historically been exploited as blistering and vom...

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“…Cadogan et Gosney (3) ont Ct C parmi les premiers a I'utiliser dans la chimie de I'arsenic, a partir d'arylazotures contenant des groupes attracteurs d'electrons. Cependant, les arsinimines sont obtenues le plus souvent par action d'arsanes sur des chloramines (4,5) ou par condensation d'oxydes de triarylarsane avec des isocyanates et des N-sulfinylamides (6,7).…”

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Hétérocycles organiques de l'arsenic. Synthèse d'arsinimines hétérocycliques par la "réaction de Staudinger." Mécanisme de la réaction

Maroni¹,

Madaule²,

Seminario³

et al. 1985

Can. J. Chem.

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R e~u le 24 fkvrier 1984 PIERRE MARONI, YVES MADAULE, TULA SEMINARIO et JEAN-GERARD WOLF. Can. J. Chem. 63, 636 (1985).La rCaction de Staudinger a CtC appliqute h des httCrocycles arsCniCs. L'action des azotures de picryle et de paratoluknesulfonyle sur une strie d'arsatranes tttracoordines conduit h des arsinimines originales pentacoordinCes, avec maintien de la liaison atrane N + As. Ces arsinimines se dimCrisent pour donner des diarsadiazacyclobutanes comportant des atomes d'arsenic hexacoordints. La rtactivitt des arsanes est plus faible. Seul I'azoture de picryle donne lieu h reaction. Les arsinimines obtenues se dimtrisent plus ou moins rapidement dans pratiqucment tous les cas, sauf un ou I'arsinimine reste sous forme monomkre. L'Ctude de la reaction en ultraviolet permet de mettre en dvidence un complexe intermtdiairc, difftrent de celui de la reaction "classique" dcs homologues phosphorCs. Staudinger's reaction is applied on arsenic heterocycles. Picryl and tosyl azides lead, by action on tetracoordinated arsatranes, to previously unknown pentacoordinated arsinimines with an "atran" bond ( N + As). In a sccond step, they dimerize to diarsadiazacyclobutanes, bearing hexacoordinated arsenic atoms. Heterocyclic arsanes react only with picryl azide. Pour notre part nous avons applique la reaction de Staudinger ii la synthese d'arsinimines heterocycliques originales, e n faisant agir des azotures sur des heterocycles organiques de I'arsenic appartenant a deux grandes series: (i) des arsatranes, composes originaux stables de I'arsenic tttracoordint synthCtisCs au laboratoire (8) azotures.Pour obtenir ces nouvelles arsinimines hCttrocycliques, pour lesquelles l'arsenic est relie a d'autres hetCroatomes (N, 0 ) nous avons opere par voie thermique et photochimique.La gamme des azotures utilisables est relativement large. For personal use only.

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Carbodiimides. III. Conversion of Isocyanates to Carbodiimides. Catalyst Studies

Cited by 111 publications

References 1 publication

What factors control the mechanical properties of poly (dimethylsiloxane) reinforced with nanosheets of 3-aminopropyltriethoxysilane modified graphene oxide?

What factors control the mechanical properties of poly (dimethylsiloxane) reinforced with nanosheets of 3-aminopropyltriethoxysilane modified graphene oxide?

Arsenous chloride-free synthesis of cyclic tertiary organoarsines from arylarsine oxides and di-Grignard reagents

Hétérocycles organiques de l'arsenic. Synthèse d'arsinimines hétérocycliques par la "réaction de Staudinger." Mécanisme de la réaction

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