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.     

Halogenotropy in Phosphorus-Carbon Diad

Abstract

NMR and chemical studies have shown that α-halogenoalkyl-phosphines 1 and P-halogenoylids 2 exist as halogenotropic tautoineric systems. The position of the equilibrium depends on the used solvent, temperatures and substituents at the α-carbon atom. For example, the equilibrium 1 2 shifts towards the phosphine from 1 if the substituents at the α-carbon atom are electron-donating (R = H, Me, Pr, i-Pr). These compunds, existing preferably in the phosphine form, undergo typical reactions both for tervalent phosphorus compounds and P-halogenoylids. Tervalent phosphorus compounds, α-halogenoalkylphosphines 1 add sulfur and react with anhydrous HCl to convert into the dichlorophosphines -4. Like the P-halogenoylids, they add alcohols and phenols forming the phosphonium salts 5, 6, react with primary amines and aniline to yield the iminophosphonates 7 They also form the 2-halogenoalkylphosphonates 8 in the reaction with aldehydes.     

α,β- and β,γ-unsaturated phosphonium salts in reactions with halogenating agents

Reaction of 1,4-bisphosphonium salts containing common buta-1,3-dienylene group with the halogenating agenst such as halogens and copper halides is studied. It was found than in all the cases instead of the expected products of the 1,2- or 1,4-addition to the above-mentioned salts the adducts with complex anions were formed quantitatively. According to the X-ray studies of bis(tributylphosphonio)buta-1,3-dienotribromocuprate the positive charge on phosphorus is compensated with the complex [Cu₂Br₆]²⁻ anion.     

Über Ligandenumverteilungsreaktionen an ternären Siliciumtetrahalogeniden in Gegenwart von Pyridin

On Ligand-Rearrangement-Reactions at Mixed Silicon Tetrahalides in the Presence of Pyridine The exchange of substituents on mixed silicon tetrahalides completely takes place after few hours in CHCl₃ at 334 K in presence of small quantities of pyridine or pyridinium salts. The exchange equilibria does not deviate much from the values expected from ideal random sorting. Mixed silicon tetrahalides are stable for some days at 298 K in CHCl₃ in presence of pyridine or pyridinium salts respectively, so that by the reaction of binary silicon tetrahalides (SiBr₄, SiI₄) with (pyH)Cl all mixed silicon tetrahalides may be identified side by side. A separation by destillation of the mixtures is impossible because of easy dismutation reactions in presence of pyridine. The influence of pyridine takes place presumable above the formation of addition compounds.     

Synthetic and mechanistic aspects of halo-F-methylphosphonates

The synthesis of a variety of new halo-F-methylphosphonates has been achieved by a Michaelis-Arbuzov type reaction between a halo-F-methane and a trialkyl phosphite. This synthesis has proved to be of wide scope and utility for the high yield preparation of a number of heretofore unknown compounds. The ¹H, ¹⁹F, ¹³C and ³¹P NMR spectroscopic properties are reported in detail. The mechanism for the formation of bromodifluoromethylphosphonates has been shown to proceed through the intermediacy of difluorocarbene:CF₂. The phosphonate products have been shown to react with a wide variety of reagents. Fluoride and alkoxide ions react by attack at phosphorus with cleavage of the carbon-phosphorus bond and formation of [:CF₂] from the bromodifluoromethylphosphonates and the CFBr₂⁻ anion from the dibromofluoromethylphosphonates. Iodide ion and tertiary phosphines react by attack at the ester carbon to give stable phosphonate salts. Hydrolysis of the phosphonate esters with 50% aqueous HCl gives the expected phosphonic acids. Trimethylsilyl bromide attacks phosphoryl oxygen to afford the bis(trimethylsilyl) esters.     

Facile Syntheses of N‐Heterocyclic Carbene Precursors through I2‐ or NIS‐Promoted Amidiniumation of N‐Alkenyl Formamidines

We have developed I₂‐ or N‐iodosuccinimide (NIS)‐mediated amidiniumation of N‐alkenyl formamidines for the syntheses of cyclic formamidinium salts, some of which could be directly used as N‐heterocyclic carbene (NHC) precursors. Treatment of iodine‐containing formamidinium salts with Al₂O₃ led to the formation of cyclic formamidinium salts with an unsaturated backbone. A rhodium(I) complex ligated by a representative NHC was prepared by the reaction of [Rh(cod)Cl]₂ (cod=1,5‐cyclooctadiene) with the free carbene obtained in situ from deprotonation of the corresponding formamidinium salts. The NHCs prepared in situ can also react with S₈ to afford the corresponding thiones.     

Ruthenium‐Catalyzed synthesis of quinolines from anilines and N‐allylic compounds by cascade amine exchange reaction‐heteroannulation

Anilines react with N‐allylic compounds such as triallylamine and N,N‐diallylaniline in dioxane in the presence of a catalytic amount of ruthenium(III) chloride hydrate and bis(diphenylphosphino)methane and tin(II) chloride dihydrate to afford the corresponding quinolines in high yields. Several other phosphorus ligands are also effective, but bis(diphenylphosphino)methane is the ligand of choice. A reaction pathway involving cascade amine exchange reaction‐heteroannulation is proposed for this catalytic process.     

Interaction of Tertiary Phosphines with Acetylenic Compouxds. Alkyl Migration Accompanied by C-P Bond Cleavage and Fragmentation During the Interaction of Trialkyphosphines with Phenylacetylene in the Presence of Proton Donors

Abstract

We have recently describedphosphobetaines with negative charge on β-carbon atom of vinyl group or on δ-carbon atom of l 1,3-butadienyl group prepared by interaction of trial-kylphosphines with acetylenic and vinylacetylenic compounds, respectively. In the course of developing these investigations an extra route of phosphobetaine formation has been found representing the deprotonation of corresponding phosphonium salts. It has been found that the reaction of trialkylphospliines with phenylacetylene in the presence of proton donors leads to the formation of an intermediate compound containing pentacovalent phosphorus linked with negatively charged oxygen atom. The intermediate undergoes a migration of alkyl group followed either by protonation of β-carbon atom or by unusual cleavage of P-C bond as a result of the electrons back transition:     

Synthesis and Rearrangement of N-PIII-Phosphorylated Carboxylic Acid Amides

Abstract

Reactions of carboxylic acid lactams with tervalent phosphorus chlorides, leading to N- and/or O- derivatives have been investigated. Synthetic methods for imidoylphosphites and phosphonates, mono- and bisphosphorylated azadienes have been developed. Prototropic migrations in azaallylic triad, phosphorus atom migrations in N-C-O triad and imidoylphosphite-imidoylphosphonate rearrangement were found. It was encountered, that chlorination of amidophosphites containing one to three trihalogen acetamide groups is accompanied by chlorine or N-acylamide group shift and leads to cyclic and spirocyclic phosphoranes with 1,3,2-⁵-oxazaphosphetanic cycle.     

Reactions ANC Rearangements of Carboxamides Phosphorylated by Tervalent Phosphorus Chlorides

Abstract

We have found that N-substituted amides of carboxylic or thiocarboxylic acids (I) react with tervalent phosphorus chlorides to give N- and O(S)-phosphorylated derivatives (II) which isomerise into imidoyl(thio)phosphonates (III). The factors determining the ability of the initial products (II) and their iminated derivatives (IV) to participate in diad and triad rearrangements have also been studied.     

MECHANISM OF THE REACTION OF DIPHENYL N-BROMOSULFILIMINE WITH SULFIDES,PHOSPHINES AND TERTIARY AMINES

Abstract

The mechanism of the reactions of diphenyl N-bromosulfilimine (I) with such nucleophiles as sulfides, phosphines and tertiary amines was investigated. In the presence of water, (I) reacts with sulfides or phosphines to afford the corresponding sulfoxides or the phosphine oxides in moderate yields; however, the reaction with tertiary amine gave only the N-t-aminosulfilimine derivative. The effect of ring size in the reaction with cyclic sulfides suggests that the reaction proceeds via initial bromine transfer from the nitrogen atom to the sulfur atom of the cyclic sulfides followed by S_N2 type substitution of bromide on the sulfur atom of the cyclic sulfide with the sulfilimino group. The phosphine oxide obtained in the reaction of (I) with optically active methyl n-propyl phenyl phosphine was racemized but retained a small portion of the optical activity. In the case of tertiary amines, even 1,4-diazabicyclo-(2,2,2)-octane (DABCO), in which the back side of the nitrogen atom is blocked, reacted smoothly to afford the corresponding ammonium salts, suggesting the reaction to be of S_N2 type on the nitrogen atom of the sulfilimine.     

ipso- and tele-Substitution in reactions of 3-chloro-1-ethyl-2-R-pyrazinium salts with C-nucleophiles

The reactions of 2,3-dichloro- and 3-chloro-1-ethyl-2-morpholinopyrazinium tetrafluoroborates with compounds containing the active methylene group were studied. The reactions with malonodinitrile and cyanoacetic ester afford products of ipso-substitution at position 2, while 1,3-dicarbonyl compounds produce products of tele-substitution of the Cl atom at the C(3) atom due to the attack of a nucleophile to position 6 of the pyrazine cycle.     

Chemical properties of 3a,6a-diaza-1,4-diphosphapentalene. Addition of polyhalohydrocarbons

3a,6a-Diaza-1,4-diphosphapentalene (DDP, 1), in contrast to common azaphospholes, readily reacts with polyhalohydrocarbons with the formation of 1,1- or 1,4-addition products at the phosphorus atoms. Dibromomethane gives the substitution product of two bromine atoms [CH₂(DDP)₂]Br₂ (2) and diphosphine (DDP-DDP)Br₂ (3) containing a bridging bromine atom. In the course of the reaction of DDP with CF₂Br₂, two products of sequential substitution of the bromine atoms were isolated, which are 1,4-Br₂(DDP) (6) and [CF₂(DDP)₂]Br₂ (7). Tris(pentafluorophenyl)phosphine reacts with DDP at the C—F bond with the formation of 1,1-addition product 8. Compounds 2, 3, 7, and 8 contain hypervalent (tervalent 4-coordinated) phosphorus atoms. X-ray diffraction data indicate that the mutual arrangement of the DDP fragments in compounds 2, 3, and 7 is determined by the non-covalent interaction of one of the bromine atoms simultaneously with two phosphorus atoms of different DDP fragments in such a way that the lines of the N—P bonds converge at this bromine atom.     

A study on the reaction of silicon tetrahalides with phosphorus pentoxide and of alkali metal fluorosilicates with phosphorus pentoxide and sulphur trioxide

Silicon tetrahalides, SiX₄ (X=F, Cl, Br) and the fluorosilicates of sodium and potassium react with phosphorus pentoxide above 300°C. The tetrahalides give rise to the corresponding phosphoryl halides and silica, while the fluorosilicates form the corresponding metal fluorophosphates and silicon tetrafluoride. The reaction of the fluorosilicates of sodium and potassium with sulphur trioxide occurs at room temperature to give rise to the corresponding metal fluorosulphates and silicon tetrafluoride.     

Reaction of methyl-substituted pyrylium salts with tertiary amines

2,4,6-Trimethylpyrylium perchlorate reacts with heterocyclic compounds containing apyridine nitrogen atom and having basicities higher than 9 pK_a units (in acetonitrile) through a step involving the formation of a methylenepyran. 4-Methyl-2,6-diphenyl- and 2-methyl-4,6-diphenylpyrylium perchlorates react with benzimidazole to give 1,2-ethanediylidenebispyrans. Methyl-substituted pyrylium salts react with 2,6-diphenylpyrylium and flavylium perchlorates in the presence of benzimidazole to give methylidynecyanines and with acetic anhydride to give trimethylidynecyanines.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1484–1489, November, 1976.     

α,ω-Bis(Dialkylthiophosphoryl)Sulfanes-Products of the Alcoholysis of Sulfur-Rich Phosphorus Sulfides

Abstract

The high solubility of sulfur-rich phosphorus sulfides in CS₂-especially in the range S:P=2.7 to 4-is the motive for new investigations on this system. DEMARCQ¹ suppsed the existence of “molecular products”, but he coulds not prove it by spectroscopic and chemical methods. As we have found the formation of α, ω-bis (fluorodithicphosphoryl) oliqosulfanes at the nucleophilic degradation of phosphorus sulfides with fluorides gives no proof for the existence of oligosulfane bridges in the sulfur-rich phosphorus sulfides. On the reaction of P₄S₁₀, elementary sulfur and alka-lifluorides the same products are formed. Sulfur-rich phosphorus sulfides and alcohols also react to mixtures of α,ω-bis (dialkylthiophosphoryl)sulfanes. But these compounds are not obtained by the reaction of P₄S₁₀ and sulfur with alcohols.     

Pyranylidene iminium salts II. Iminium salts derived from pyrones,dialkylamides and phosphorus oxychloride

N,N-Dialkylamides, pyrones, and phosphorus oxychloride react to give pyranylidene chloroiminium salts. The chlorine atom of these salts is readily displaced by nucleophiles to yield a variety of pyranylidene derivatives.     

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.     

An Expedient Synthesis of Allylic/Secondary Bromides from Dehydration of Tertiary-β-bromo Alcohols

Abstract

Tertiary-β-bromo alcohols, derived from simple monoterpenes and olefins, react with BF₃.OEt₂ in refluxing benzene in 1–2 h to afford the corresponding allylic/secondary bromides in 45–90% yield. In case of substrates containing olefinic or hydroxyl groups, formation of cyclic ethers was observed.     

Condensed isoquinolines 31. Reaction of 5-aryl-3-halo-12H-isoquino[2,3-a]quinazolines with electrophilic reagents

Treatment of 5-aryl-3-halo-12H-isoquino[2,3-a]quinazolines with electrophilic reagents readily forms their oxidation products. Acylation of the 3-chloro-5-phenyl-7,12-dihydroisoquino[2,3-a]quinazolinium perchlorate with Ac₂O in the presence of pyridine gave the product of electrophilic substitution at the C-7 atom 1-(3-chloro-5-phenyl-12H-isoquino[2,3-a]quinazolin-7-yl)-1-ethanone. By the same route phenacyl bromides react with the anhydro base 1 to give 5-aryl-7-(2-aryl-2-oxoethyl)-3-halo-isoquino[2,3-a]quinazolin-13-ium bromides. These salts readily react with nucleophilic reagents to form the products of addition at the C-12 atom. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 1044–1052, July, 2008.