New Types of Functionally Substituted Methylphosphonites and Their Derivatives

Abstract

Organophosphorus compounds containing a functional group in the a-position of the alkyl radical are of great interest in both theoretical fundamental investigations and for practical applications. Functionally substituted methyl-phosphonites and their derivatives, belonging to this broad class of organophosphorus compounds, are convenient objects for investigating mutual effects of trivalent phosphorus and a heteroatom, or functional groups attached to it in the a-position. They have also become key substances in obtaining new organophosphorus compounds. Functionally sub-stituted compounds of tetracoordinated phosphorus have been intensively investigated in recent years; rather convenient methods of synthesis of these compounds have been proposed and their properties have been studied in detail¹. However, the corresponding compounds of tricoordinated phosphorus are not available or difficult to obtain. Recently we re-ported on the properties of halogen-substituted methylphos-phines and their derivatives². The present paper is devoted to the synthesis and investigation of the reactivity of alkoxy-, dialkylamino- and carbonyl substituted methylphos-phonites and their derivatives. In synthesis of alkoxymeth-ylphosphonites and their analogs we were the first to use labile alkoxymethylmagnesium chlorides in the reactions with tricoordinated phosphorus acid chlorides³. Previously unknown dialkoxymethylphosphonites and their analogs were obtained from hypophosphorous acid and trialkylorthofor-mates. The process of esterification and dialkoxymethylat-ion of hypophosphorous acid, being dependent on a catalyst, proceeds in different ways and results in the formation of dialkoxymethylphosphonite structures     

Phosphorus ozonides adducts

Abstract

Ozone reacts quantitatively on tricoordinated and dicoordinated Phosphorus Compounds. The oxidative addition of ozone on phosphites leads to pentacoordinated or hexacoordinated phosphorus adducts. These adducts are unstable in solution. The decomposition gives the corresponding phosphoric ester with singlet oxygen evolution. In the same conditions, ozone reacts on diphosphene and gives after double bond rupture an adduct: the metaphosphonate. The relative stabilities and oxidative properties are discussed.     

Use of Pentacovalent Oxaphosphorane Chemistry in the Development of New Methodology for the Synthesis of Natural Products

Abstract

We are presently studying pentacovalent phosphorus chemistry for the design and development of new reagents and methods for organic synthesis. We have found that the condensation reactions between aldehydes and 2,2,2-trialkoxy-1,2-oxa-phospholenes, A1b, yield p-hydroxy ketones (aldols) that contain an a-methylene-phosphonate group in good to fair diastereomeric ratios. The syn diastereomer was the major product. This Is contrary to the results published by Ramirez using 2,2,2-trlalkoxy-1,3,2-dioxaphospholenes, A1a, and various carbonyl compounds, where the anti isomer was the major product. Use of 2,2,2-trialkoxy-1,3,2-oxazaphospholenes, A1c, yields a-amino p-hydroxy carbonyl compounds. Application of this carbonyl condensation reaction to the short and efficient syntheses of cis- and trans-neocnidilide will be illustrated. Formation of chlral phosphorus In splrophosphoranes by the arresting of pseudorotation around the phosphorus has been accomplished In 1,3,2-dIoxa-phosphoienes with ephedrine as a bldentate llgand (Bl, 82, 83). The lack of pseudorotation has been demonstrated by variable temperature NMR studies. All of these results will be presented and discussed.     

Synthesis of Some New Triphenylphosphanylidenes,Alkylphosphonates, and Heterocycles of Pyrazole Derivatives and Their Antimicrobial Activity

Abstract

The reaction of 5(4H)-pyrazolone with phosphorus ylides afforded new triphenylphosphanylidene alkanone derivatives. Moreover, its benzylidene derivative reacted with Wittig–Horner reagents to give the corresponding dialkoxyphosphoryl, alkyl phosphonate, and heterocyclic products. Treatment of pyrazole-4-carbaldehyde with Wittig–Horner reagents and trialkyl phosphites gave the respective alkyl phosphonate adducts. Mechanisms accounting for the formation of the new products are discussed. The biological activity of some of the newly synthesized compounds was also examined.     

ON THE NATURE OF THE NUCLEOPHILE IN THE MIXTURE OF PHOSPHITES AND AMINES

Abstract

It is now commonly accepted that in the presence of strong bases (like metal alcoholates) an equilibrium between phosphite and phosphonate forms of dialkyl phosphites exists and that the phosphite form is highly reactive in the reaction with carbonyl compounds. There is a controversy on the structure of the active form of the phosphite when the addition is catalyzed by amines. We have found that aliphatic amines and dialkyl phoshites form a complex which is a reactive species. Its stoichiometry depends on the nature of the solvent.     

Novel Ylidic Phosphoryl Compounds from Halogenated Furan-2,5-Diones with Trivalent Phosphorus Esters: Application of this Approach to New Trisphosphonates Containing a Geminal Bisphosphonate Unit

Abstract

The reactions of trivalent phosphorus esters, including trialkyl phosphites, dialkyl phosphonites, and alkyl phosphinites, with 3-halo- and 3,4-dihalo-furan-2,5-diones has been shown to lead to the formation of novel phosphorus ylides possessing additional phosphoryl-containing groups. For the reaction of 3,4-dihalo-furan-2,5-diones with trialkyl phosphites, the products are trialkoxyphosphonium ylides containing an adjacent geminal bisphosphonate unit. These can be used to provide a convenient route to novel 2,3,3-tris(dialkoxyphosphoryl)-substituted propionate esters which can be hydrolyzed to give the corresponding novel trisphosphonic monocarboxylic acid.     

SYNTHESIS AND CONFORMATIONAL STUDIES OF A NUMBER OF SATURATED BICYCLIC SIX-MEMBERED RING PHOSPHITES

Abstract

An ¹H NMR study of the conformation of the dioxaphosphorinane ring of a number of diastereoisomeric bicyclic saturated six-membered ring phosphites (3ab-10ab) has been performed. The dioxaphosphorinane ring of these phosphites is transannelated with a tetrahydrofuran, cyclopen-tane, tetrahydropyran or cyclohexane ring. The substituent on the phosphorus atom is a methoxy or phenoxy group. It is shown that the cis isomers 3a-10a prefer a chair conformation of the dioxaphosphorinane ring, independent of the substituent on the phosphorus atom and of the nature of the transannelated ring. In contrast, for the trans isomers 3b-10b a twist rather than a chair conformation of the dioxaphosphorinane ring is preferred. The fraction of the twist conformer in the trans isomers is mainly determined by the substituent on phosphorus. The size and composition of the transannelated ring are relatively unimportant in this respect. For both cis and trans isomers the preferred geometry is solvent-independent. The measured ^3JPOCH couplings of the cis isomers 3a-10a are used to formulate an expression for the dependence of such couplings upon dihedral angles in bicyclic phosphites.     

ORGANOPHOSPHORUS COMPOUNDS,XXXIII THE REACTION OF PHOSPHITE ESTERS WITH QUINISATIN

Abstract

Trialkyl phosphites react with quinisatin (1) and its monohydrate 3 to give the corresponding phosphate derivatives 2a-c. The same compounds are obtained upon reacting 1 and/or 3 with the proper dialkyl phosphite. Structural reasonings based on IR, MS and NMR spectral data, are presented.     

SPIROPHOSPHORANES A LIAISON P–H D'α-HYDROXYACIDES ET DE TARTRATES D'ALCOYLE: PREPARATION,PROPRIETES—STEREOCHIMIE

Abstract

About twenty spirophosphoranes bearing a P–H bond have been obtained by the reaction of α-hydroxyacids or alkyl tartrates on tricoordinated phosphorus compounds. The stereochemistry is described. Intra- or extracyclic carbonyl groups, especially in the case of two identical ligands, increase the Lewis acid character of the phosphorus atom.

Une vingtaine de spirophosphoranes à liaison P–H ont été préparés en faisant réagir des α hydroxyacides ou des tartrates d'alcoyle sur des substrats à phosphore tricoordiné convenables. L'étude stéréochimique systématique de ces composés est décrite. La présence des groupements carbonyle a pour influence de renforcer le caractère d'acide de Lewis de l'atome de phosphore, notamment dans le cas des composés contenant deux ligands identiques, que le carbonyle soit intra ou extracyclique.     

The influence of the sacrificial anode nature on the mechanism of electrochemical arylation and alkylation of white phosphorus

The material of the sacrificial anode has a substantial effect on the nature and yield of the target products of electrochemical phosphorylation of organic halides by white phosphorus in the presence of the nickel complexes with 2,2"-bipyridine. The use of the zinc anode results in the products with tricoordinated phosphorus, viz., triorganylphosphines, the reaction on the aluminum anode affords triorganylphosphine oxides, and the presence of Mg²⁺ ions in the reaction mixture provides the transformation of white phosphorus into cyclic phosphines (PhP)₅.     

STEREOCHEMISTRIES OF SOME REACTIONS OF CYCLIC STEREOISOMETRIC PHOSPHITES

Abstract

The reaction of the isomeric phosphites, 1 and 2, with ozone have been shown to be stereospecific and to proceed with retention of configuration about phosphorus. Similarly ozonization of mixtures of 3 and 4 were found to be stereospecific or very nearly so with retention of configuration about phosphorus. The mechanistic implications of these findings are discussed. Reactions of 1 and 2 with neopentyl and t-butyl hypochlorites proceed in a stereochemically random manner. The formation of a pentacoordinated intermediate is implicated. Reactions of a mixture of 1 and 2 with ethyl thiyl radicals provided phosphorothionates with complete retention of configuration.     

Novel Approach to the Synthesis of Phosphorus Sulfur Organic Compounds and Their Metal Complexes

Abstract

The reaction of elemental phosphorus (P_{ti 4}) and sulfur with protonodonor reagents (alcohols, phenols, and thiols) has been studied in the presence of amines and complexes based on trialkyltrithiophosphites and transition metal halides. A novel approach to the synthesis of phosphorus sulfur organic compounds has been proposed on the basis of these reactions.     

Copper/DIPEA-catalyzed, aldehyde-induced tandem decarboxylation-coupling of natural α-amino acids and phosphites or secondary phosphine oxides

A copper/DIPEA-catalyzed, aldehyde-induced intermolecular decarboxylative coupling reaction of natural α-amino acids and phosphites or secondary phosphine oxides was developed. In this process, a series of potentially useful ligands for organic synthesis and biologically important unnatural amino acid derivatives (tertiary amino phosphorus compounds) were obtained.     

New Sulfur and Phosphorus Containing Metal Complexes on the Basis of Trithiophosphites. Synthesis and Properties

Abstract

New sulfur- and phosphorus containing metal complexes have been obtained by means of reactions of trialkyl- and triaryltrithiophosphites with transition metal halides. Their reactions with proton containing and carbonyl compounds have been studied.     

Clay Catalysis: Synthesis of Organosulphur Synthons

Abstract

The Montmorillonite KSF catalyses the synthesis of a large variety of organic sulphur compounds from carbonyl compounds: dithianes, thioacetals, thioketals, thiochromanes.

Clay minerals are known to cataiyse a variety of organic reactions(1). In these reaction, the clay catalyst acts as a solid Bronsted acid. One of the most acidic, Montmorillonite manufactured by Sud Chemie, is the KSF catalyst. Clay is inexpensive and offers several advantages to the classic acid: a strong acidity (Ho = ?8 to ?9), no corrosive action, selectivity and easy work-up.

We report here, that KSF clay is a convenient catalyst for the synthesis of useful thio-organic reagents : dithianes, thioketals, trithioorthoformiates, thiochromanes. The condensations of the thiol with the carbonyl compounds were completed in refluxing toluene in presence of KSF with the azeotropic separation of water. Generally the pure compound was obtained in these reactions and the work-up very simple.     

双环笼状磷酸酯衍生物的研究Ⅵ:4-取代-2,6,7-三氧杂-1-磷杂双环[2.2.2]辛烷的反应研究

双环笼状亚磷酸酯类衍生物由于其笼状结构所引起的张力及高位阻性 ,使得它同一般直链亚磷酸酯类化合物相比,在亲核取代反应性等方面有关明显的不同.本文用化合物1分别同SO~2Cl~2,Cl~2, Br~2, PCl~5等反应,结果表明,1均发生了类Arbuzov反应,生成具有相同立体构型的开环产物.本文还对化合物2的磷酰化反应进行了研究,发现在这类高位阻性的双环笼状亚磷酸酯衍生物的磷酰化反应中,DMAP是一个较有效的催化剂.     

Arylation catalytique d'organophosphorés. Produits de l'arylation,catalysée par les sels de nickel (II), de composés du phosphore tricoordiné.

Analysis of the products from the nickel (II) bromide catalysed arylation of tricoordinated phosphorus compounds R₂P-Z (Z  H, Cl, SR, NR₂ pointed out that this arylation always takes place on phosphorus resulting at first in formation of pseudophosphonium salts. Only the aminophosphonium salts are stable under reaction conditions; the other salts undergo several transformations which can be brought together in a general reactivity scheme to account for all the side products. On regard to other heteroatoms these results point out a particular ability of phosphorus to be arylated under nickel (II) catalysis.The reaction with secondary phosphines can be applied to synthetise diarylphosphonium salts.     

ELECTRON TRANSFER REACTIONS OF METAL CARBONYL ANIONS

Abstract

Metal carbonyl anions exhibit one- and two-electron reactions. The two-electron processes involving transfer of groups (hydrogen, alkyl, and halogen) between metal centers are related to the nucleophilicity. The one-electron processes are primarily outer-sphere electron transfer for the metal carbonyl anions. These reactions are observed in the presence of oxidants such as coordination complexes, pyridinium salts, metal carbonyl dimers and metal carbonyl clusters. However, in contrast to organic reactions, the metal carbonyl anions may undergo inner-sphere electron transfer. Reactions of metal carbonyl anions of low nucleophilicity with metal carbonyl cations or halides are best interpreted as inner-sphere, one-electron transfer.