N → C2 → C3 migration of the dichlorophosphino group in the synthesis of phosphorylated NH‐pyrroles

A successive N → C₂ → C₃ migration of the dichlorophosphino group has been found to occur in phosphorylation of unsubstituted pyrrole with phosphorus trichloride. As a result of this migration, a number of hitherto unknown C‐phosphorylated N‐unsubstituted pyrroles have been obtained. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:671–676, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20495     

One-Pot Synthesis and Fungicidal Activity of Pyrimidinylidenamido- and Thiazolinylidenamidomonothiophosphoric Esters

A novel one-pot synthesis of four new classes of amidothiophosphoric esters and trisamidothiophosphoric esters is developed. (1-Alkyl-2-pyrimidinylidenamido)bis(diethylamido)thiophosphates, (1-alkyl-2-pyrimidinylidenamido)bis (O-2/4-methylphenyl)thiophosphates, (3-alkyl-2-thiazolinylidenamido)bis (diethylamido)thiophosphate and (3-alkyl-2-thiazolinylidenamido)bis(O-2/4-methylphenyl)thiophosphates are obtained from the nucleophilic substitution and oxidation of N-alkyl-2-cycloiminylidenaminodichlorophosphines generated in situ from the reaction of the corresponding N-alkyl-2-aminocycloiminium halide with phosphorus trichloride and triethylamine. The synthesized thiophosphoric esters have been investigated for fungicidal properties.     

Synthesis and characterization of novel (9H‐fluoren‐9‐ylamino) carbonylaminomethylphosphonic acid

The new α‐aminophosphonic acids are synthesized, reacting (9H‐fluoren‐9‐yl)urea with formaldehyde and phosphorus trichloride. (9H‐Fluoren‐9‐yl)urea was prepared from spiro(fluoren‐9,4′‐imidazolidine)‐2′,5′‐dione by alkaline hydrolysis with Ba(OH)₂. The structure of the title compounds was proved by means of IR, ¹H, ¹³C, and ³¹P NMR spectroscopy. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:719–722, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20500     

One-pot synthesis of new 6-(alkylamine)dibenzo[c,e][1,2]oxaphosphinine-6-oxides

Several new 6-(alkylamine)-6H-dibenz[c,e][1,2]oxaphosphinine-6-oxides were prepared through a one-pot reaction, starting with 2-phenylphenol, phosphorus trichloride, and a Zn catalyst, to form 6-chloro-6H-dibenz[c,e][1,2]oxaphosphine. The alkylamine derivatives were subsequently prepared through a nucleophilic substitution reaction involving aliphatic amines and H₂O₂ oxidation under soft conditions. This method has the advantages that it is a one-pot synthesis, does not require an inert atmosphere, and involves in situ catalyst formation.     

Sequential Nucleophilic Substitution of Phosphorus Trichloride with Alcohols in a Continuous-Flow Reactor and Consideration of a Mechanism for Reduced Over-reaction through the Addition of Imidazole

We demonstrate a sequential nucleophilic substitution of highly electrophilic and inexpensive phosphorus trichloride with three different alcohols in a continuous-flow reactor. A variety of alcohols including ones that contained acid- and/or basic-labile functionalities were rapidly reacted. A over nucleophilic substitution that occurred during reaction of the second alcohol was suppressed by the addition of imidazole. Density functional theory calculations of the sequential nucleophilic substitutions of alcohols were performed both with and without imidazole, and Berry pseudorotation was suggested as a rate-limiting step in both cases. Herein, we discuss the reasons for the decreased selectivity in the absence of imidazole as well as those for improved selectivity in the presence of imidazole during the second nucleophilic substitution.     

Synthesis of phosphorous acid and its derivatives based on the reaction of elemental phosphorus (P4) and aqueous solution of choline in the presence of the hydroxides of earth alkali metals

A nonchloric method for the synthesis of phosphorous acid and barium and calcium phosphites is proposed, involving the reaction of elemental phosphorus (P₄) with aqueous barium and calcium hydroxides in the presence of quaternary ammonium base (choline). Conditions for the preparation of high‐purity phosphorous acid based on the oxidation of the hypophosphite ion to the phosphite ion in a strong alkali medium were studied. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:517–519, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20472     

N → C3 migration of dichlorophosphino group in the phosphorylation of N‐unsubstituted indole with phosphorus trichloride

A N → C₃ migration of the dichlorophosphino group has been revealed in the phosphorylation of unsubstituted indole with phosphorus trichloride. Several 3‐phosphorylated NH‐indole derivatives have thus been obtained and N‐acylation of one of the products has been performed. © 2009 Wiley Periodicals, Inc. Heteroatom Chem 20:235–239, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20540     

Organophosphorus Synthesis Without Phosphorus Trichloride: The Case for the Hypophosphorous Pathway

Abstract

The vast majority of organophosphorus compounds is currently synthesized from phosphorus trichloride (PCl₃), even though the final consumer products do not contain reactive phosphorus–chlorine bonds. In order to bypass phosphorus trichloride, significant interest has been devoted to functionalizing elemental phosphorus (P₄, the precursor to PCl₃), red phosphorus (P_red), or phosphine (PH₃). Yet, other industrial-scale precursors are hypophosphorous derivatives (H₃PO₂ and its alkali salts), but their use as phosphorus trichloride replacements has been completely overlooked. Here, the case is made for an alternative approach to the industrial synthesis of organophosphorus compounds based on hypophosphites.     

Phosphorylation of five-membered aromatic heterocycles with phosphorus tribromide

Phosphorus trichloride in a basic medium is a convenient reagent for the direct C-phosphorylation of electron-rich aromatic heterocycles. The compounds obtained can be used for the synthesis of various types of heteroaryl and diheteroaryl derivatives of tri- and pentavalent phosphorus. © 1995 John Wiley & Sons, Inc.     

Phosphorylation of N‐iso‐propyl‐ and N‐tert‐butylpyrroles with phosphorus(III) halides

The investigation concerns the effect of a bulky substituent at the pyrrole nitrogen atom on the orientation and regioselectivity of pyrrole phosphorylation with phosphorus(III) halides. As shown, phosphorylation of N‐iso‐propylpyrrole with phosphorus tribromide or trichloride proceeds nonregioselectively at positions 2 and 3 but it is followed by the 2 → 3 migration of the dihalogenophosphine group which quantitatively yields the 3‐isomer. N‐tert‐butylpyrrole is regioselectively phosphorylated with halogenophosphines at position 3. The tert‐butyl substituent at the nitrogen atom does not preclude the binding of even two or three pyrrolyl residues to the phosphorus atom. The key compounds, 3‐pyrrolyldihalogenophosphines, were isolated in a pure state, characterized and used to obtain a number of stable phosphorus(V) derivatives. © 2005 Wiley Periodicals, Inc. Heteroatom Chem 16:599–604, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20158     

Isomerization of 1-oxo-1-chlorophospholenes in the presence of phosphorus trichloride

The isomerizing action of phosphorus trichloride on phospholene derivatives was observed. It was shown that mixtures of isomers, with predominance of 2-phospholene, are formed when isomerically pure 1-oxo-1-chlorophospholenes are heated in the presence of phosphorus trichloride.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1616–1619, December, 1971.     

Synthesis and characterization of poly(ethylene glycol) derivatives

Five general routes for the preparation of polyoxyethylene [generally referred to as poly(ethylene glycol) or PEG] derivatives are described. These routes are (1) nucleophilic displacements with the alkoxide of PEG, (2) nucleophilic displacement on PEG–tosylate, –mesylate, or –bromide, (3) reductive amination of PEG–aldehyde, (4) reductive amination of PEG–amine, and (5) nucleophilic displacements on the s-triazine derivatives prepared from s-triazine trichloride (cyanuric chloride) and PEG. Eighteen derivatives are prepared and potential applications to catalysis, cell purifications, and other areas are discussed briefly.     

Reaction of oxophosphoranesulphenyl chlorides with phosphorus trichloride : A new synthesis of dialkyl phosphorochloridothionates and their optically active analogues

The reaction of acyclic oxophosphoranesulphenyl chlorides, with phosphorus trichloride has been found to give thiophosphoryl chlorides, and phosphoryl oxychloride—the products of the exclusive deoxygenation of sulphenyl chloride. Optically active phosphonochloridothionates and phosphorochloridothionates in a high state of optical purity have been obtained with inversion of configuration from optically active sulphenyl chlorides and phosphorus trichloride. It has been shown, however, that cyclic oxophosphoranesulphenyl chlorides undergo simultaneous desulphurisation and deoxygenation when treated with phosphorus trichloride. Using cis- and trans-isomers of 2-chlorothio-4-methyl-1,3,2-dioxaphosphorinan-2-one it has been demonstrated that deoxygenation is accompanied by inversion, whereas desulphurisation occurs with retention at phosphorus. The mechanism of the title reaction is discussed.     

Synthesis of novel aminophosphonic acids with hydantoin structure

The novel α‐aminophosphonic acids with hydantoin structure have been synthesized reacting 5,5‐dimetylhydantoin with formaldehyde and phosphorus trichloride, or via Kabachnik–Fields reaction. Their structures were proved by means of IR, ¹H, ¹³C{¹H}, and ³¹P NMR spectroscopy. © 2009 Wiley Periodicals, Inc. Heteroatom Chem 20:87–90, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20515     

Some products of the reaction of phenylhydrazones and phosphorus trichloride

It is found that reaction of phosphorus trichloride with the phenylhydrazones of acetone, methylethyl, methylpropyl and methylbutyl ketones are compounds with one atom of phosphorus to one phenylhydrazone group. They do not contain chlorine, and distill without decomposition under vacuum. The view is advanced that they have structure I. A similar compound was also obtained by the reaction of phosphorus trichloride with acetaldehyde.     

双烷基膦酸的合成和性质研究

用格氏试剂与三氯化磷反应,继而水解、氧化,合成了3个高位阻双烷基膦酸,发现制备高位阻格氏试剂用叔氯代烷比叔溴代烷效果好;同时还用格氏试剂与亚磷酸酯反应,然后用Todd方法制备了二正辛基膦酸,发现亚磷酸二正丁酯比亚磷酸二乙酯反应效果好。此外,还考察了其1H、¹³C、³¹PNMR和酸电离性质与其取代基结构效应的关系。     

Halogen exchange reactions of silicon tetrafluoride with phosphorus trichloride and phosphoryl chloride

Silicon tetrafluoride undergoes halogen exchange reactions with both phosphorus trichloride and phosphoryl chloride at temperatures of 500–600°C yielding mixed chlorofluorides of silicon and phosphorus. It is interesting to note that, at these high temperatures, PCl₃ undergoes complete exchange to form PF₃ while POCl₃ reacts only with partial substitution, the major products being phosphorus chloride difluoride and silicon trichloride fluoride.     

One‐Pot,Four‐Component Reaction of Aryl Aldehydes,Aryl Ketones,Phosphorus Trichloride,and Acetonitrile Catalyzed by Acetyl Chloride: Synthesis of β‐Acetamido Ketones

The one‐pot, four‐component reaction of aryl aldehydes, aryl ketones, phosphorus trichloride, and acetonitrile, catalyzed by acetyl chloride, affords β‐acetamido ketones in good to excellent yields. Silicaphosphine (silphos), [P(Cl)_3‐n(SiO₂)_n], can also be used effectively as a solid‐supported reagent instead of phosphorus trichloride.     

Reactions of Halides of Tervalent Phosphorus with Imines and -Diimines

Abstract

Isobutylidenebutylamine reacts with phosphorus trichloride in the presence of organic bases to give N-butyl-N-isobutenylamidodichloro-or bis(N-butyl-N-isobutenylamido)chlorophosphites depending on the ratio of reagents. Reasons are given in Eavour of the reaction beginning with the nucleophilic attack of the nitrogen atom of the imine on the electrondeficient phosphorus atom of the chloride. Reactions of ethyldichloro- and diethylchlorophosphites with benzylidenmethylamine produce 2-chloro- and 2-ethyl-2-oxo-1,4,2-diazaphospholanes respectively. Interaction of diethylchlorophosphite with benzylidenmethylamine in the presence of triethyphosphite results in the formation of diethyl. (N-methyl-N-α-diethylphosphonobenzylamido)phosphite. As a result of interaction of bis(diethylamino)chlorophosphine with NIN-dibutyl-2,3-butandiimine in the presence of triethylamine new compounds (2-diethylamino-1,3-dibutyl-4,5-dimethyl-1,3,2-diazaphospholane and 4,8-dibutyl-3,7-bis(diethylamino)-[3.3.01-bicyclooctadiene-l15) are obtained. The structure of the latter is proved by means of ¹H, ³¹ p NMR-spectroscopy, and a complete X-ray analysis. Alkyldichlorophosphines form phosphonium salts of 1,3,2-diazaphospholene structure with a-diimines and 2-chloro-1,3-dicyclohexyl-4-chloro-1,3,2-diazaphospholene resulting from the reaction of N,N-dicyclohexylethylenediimine with PCl₃. In this product the P-C1 bond is unusually long, which is confirmed by X-ray analysis. In the course of the interaction of tervalent phosphorus halides with α,β-unsaturated imines a new reaction has been discovered with the formation of 1,2-dihydro-1,2-azaphosphorines.     

Synthesis and reactivity of alkoxy(trimethylsiloxy)phosphines and their derivatives

Convenient procedures for the synthesis of new alkoxy(trimethylsiloxy)phosphines and their derivatives starting from the available alkyl hypophosphites and N‐trimethylsilyl succinimide are proposed. Some properties of these new phosphines such as nucleophilic substitution of the trimethylsiloxy group at trivalent phosphorus, the Arbuzov reaction, and addition of PH and POSi fragments to multiple carbon–carbon bonds are presented. © 2011 Wiley Periodicals, Inc. Heteroatom Chem 23:138–145, 2012; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.20762