Reactions of Elemental Phosphorus and Phosphine with Electrophiles in Superbasic Systems: XV. Phosphorylation of Allyl Halides with Elemental Phosphorus

Elemental phosphorus (red or white) reacts with allyl chloride and allyl bromide in a two-phase system aqueous KOH-organic solvent to form tertiary symmetrical and mixed phosphine oxides among which tris(prop-2-enyl)-, bis(prop-2-enyl)[(E)-prop-1-enyl]-, bis(prop-2-enyl)[(Z)-prop-1-enyl]-, (prop-2-enyl)[(E)-prop-1-enyl][(Z)-prop-1-enyl]-, bis[(E)-prop-1-enyl](prop-2-enyl)-, bis[(Z)-prop-1-enyl](prop-2-enyl)-, tris-[(E)-prop-1-enyl]-, and bis[(E)-prop-1-enyl][(Z)-prop-1-enyl]phosphine oxides were identified. The conditions (room temperature, 60% aqueous KOH-dioxane) allowing preparation from white phosphorus and allyl bromide of tris(prop-2-enyl)- and bis(prop-2-enyl)[(E)-prop-1-enyl]phosphine oxides as major products in the total yield of up to 96% were found.     

Reactions of Elemental Phosphorus and Phosphine with Electrophiles in Superbasic Media: XI.1 Phosphorylation of 4-Methoxybenzyl Chloride with Elemental Phosphorus and Phosphine

4-Methoxybenzyl chloride reacts with elemental (red or white) phosphorus under the conditions of phase-transfer catalysis (concentrated aqueous KOH, dioxane, benzyltriethylammonium chloride, 85-90°C, argon) to give as major product tris(4-methoxybenzyl)phosphine oxide in up to 45% yield. With white phosphorus at lower (70°C) temperature this reaction yields mainly bis(4-methoxybenzyl)phosphine oxide. Phosphine reacts with 4-methoxybenzyl chloride in superbasic KOH-DMSO suspension, and under definite conditions bis(4-methoxybenzyl)phosphine oxide is predominantly formed.     

Reactions of Elemental Phosphorus and Phosphine with Electrophiles in Superbasic Systems: XIV.1 Phosphorylation of 2-Vinylnaphthalene with Elemental Phosphorus and Phosphines in the KOH-DMSO System

Elemental phosphorus (red or white) reacts with 2-vinylnaphthalene while heating at 90-96°C in the superbasic KOH-DMSO system to form 2-(2-naphthyl)ethylphosphine, 2-(2-naphthyl)ethylphosphinic acid, bis[2-(2-naphthyl)ethyl]phosphine, bis[2-(2-naphthyl)ethyl]phosphine oxide, and tris[2-(2-naphthyl)ethyl]phosphine oxide in a total yield of up to 40%. Selective conditions for preparing the tertiary phosphine oxide from white phosphorus and 2-vinylnaphthalene in 58% yield were found. Phosphine and (2-phenylpropyl)phosphine add to 2-vinylnaphthalene in the KOH-DMSO system to form, under certain conditions, corresponding secondary phosphines in high yields.     

Reactions of Elemental Phosphorus and Phosphines with Electrophiles in Superbasic Systems: XIII. Phosphorylation of Phenylacetylene with Active Modifications of Elemental Phosphorus

Phosphorylation of phenylacetylene with white or activated red phosphorus (prepared from white phosphorus under the action of ionizing radiation) occurs in KOH-DMSO or KOH-HMPA systems with heat evolution and stereoselective formation of Z isomers of tristyrylphosphine and -phosphine oxide in yields of 48-49% and 10-15%, respectively. Under the comparable conditions the commercial red phosphorus is considerably less reactive toward phenylacetylene: The total yield of the above-mentioned products is 5%.     

Reactions of Elemental Phosphorus and Phosphines with Electrophiles in Superbasic Systems: XII. Synthesis of Unsymmetrical Tertiary Phosphine Oxides from Red Phosphorus and Organyl Halides

Alkyldibenzyl- and benzyldialkylphosphine oxides were prepared in one stage by direct phosphorylation of a mixture of alkyl bromides and benzyl chloride with red phosphorus under the conditions of phase-transfer catalysis (concentrated aqueous KOH solution-dioxane-benzyltriethylammonium chloride).     

Reactions of Elemental Phosphorus with Electrophiles in Super Basic Systems: XVII. Phosphorylation of Arylalkenes with Active Modifications of Elemental Phosphorus

The example of the phosphorylation of styrene and 2-vinylnaphthalene with elemental phosphorus in the KOH-DMSO system at room or elevated temperature was used to show that the activated red phosphorus prepared from white phosphorus under ionizing radiation has a reactivity comparable with that of white phosphorus and significantly higher than that of ordinary technical red phosphorus.     

Reaction of Red Phosphorus with Electrophilic Reagents in Superbasic Systems

Abstract

A new method for generating highly nucleophilic ions from red phosphorus in superbasic systems, such as alkali metal hydroxide-dipolar aprotic solvent (HMPA, DMSO) or solvent of moderate polarity (toluene) with or without a phase-transfer catalyst, has been developed and shown to cover non-standard convenient routes to triorganylphosphines, -phosphine oxides and their derivatives. This is illustrated by the following examples:     

Photostimulated SRN 1 Reactions of Benzyl Chloride with Carbazolyl Nitrogen Anion

In recent years, the studies of the radical chain nucleophilic substitution reaction (S.. I )have been active area in both mechanism and organic synthesis'-'. The main steps of thismechanism are sketched in scheme 1.As nucleophile, various anions have been used in S.l reaction. However, thestudies of the reactions of organic nitrogen anions are not so much reported'. We have'reported that photostimulated reactions of carbazolyl nitrogen, anion with aryl handes indimethyl sulfoxide by S.l mec…     

Reactions of Nucleophiles with Nitroarenes: Multifacial and Versatile Electrophiles

In this overview, it is shown that there are many initial reactions between nitroarenes and nucleophiles: addition to the electron‐deficient ring at positions occupied by halogen and hydrogen atoms, addition to the nitro group, single‐electron transfer (SET), and other types of initial reactions. The resulting intermediates react further in a variety of ways to form products of nucleophilic substitution of a halogen atom (S_NAr), a hydrogen atom (S_NArH), and others. Many variants of these processes are briefly discussed, particularly in relation of rates of the initial reactions and further transformations.     

Use of Ferric Chloride in Carbohydrate Reactions.1 Iv. Acetolysis of Benzyl Ethers of Sugars

Acetolysis of benzyl ethers of sugars has been carried out with anhydrous ferric chloride in acetic anhydride. By employing this reagent, benzyl ether groups variously placed in sugars or in their glycosides could be removed with ease and replaced by acetyl groups. By controlled acetolysis, preferential removal of certain benzyl groups was possible. The results show that in D-glucose the relative ease of removal of benzyl ether groups by acetolysis follows the order C-6 > C-4 > C-3 > C-2 and that the rate of acetolysis is 6-O-Bn : 3-O-Bn : 2-O-Bn = 125 : 24 : 1. The corresponding methyl ethers were very sluggish towards acetolysis.     

Reactions of Ammonium Alkylene Dithiophosphates with Phosphorus Trichloride and Thiophosphoryl Chloride *

Phosphorus trichloride and thiophosphoryl chloride derivatives of alkylene dithiophosphates of the type PCl_{3 ? n} () _n and P(S)Cl_{3? n} () _n (where G = -CH₂CH₂CHMe-, -CMe₂CMe₂-, -CH₂CH₂CH₂CH₂- and -CMe₂CH₂ CHMe-, n = 1, 2, 3] have been synthesized for the first time by reacting the ammonium salt of alkylene dithiophosphoric acid with phosphorus trichloride and thiophosphoryl chloride in different stoichiometric ratios under anhydrous reaction conditions. The newly synthesized derivatives are either colorless liquids or viscous semisolids, hygroscopic in nature and are soluble in common organic solvents. These are characterized by elemental analysis, molecular weight determinations and physicochemical studies IR, NMR (¹H and ³¹P). On the basis of above studies the formation of P-S-P and S = P–S–P(S) chemical linkages have been established. ²³¹P NMR studies provide convincing evidence regarding the chemical bonding mode in these derivatives.     

Reaction of Red Phosphorus with Allylbenzene in Superbasic System KOH-DMSO

Abstract

Red phosphorus reacts with allylbenzene in the superbase system KOH-DMSO (130°C, 3 h, Ar) to give a mixture of bis(1-methyl-2-phenylethyl)phosphane (1), bis(1-methyl-2-phenylethyl)phosphane oxide (2), and 1-methyl-2-phenylethylphosphinic acid (3). Secondary phosphane oxide 2 and phosphinic acid 3 have been isolated from this mixture in 35% and 32% yield, respectively. Microwave activation of the reaction (200 W, 30 min) affords secondary phosphane 1 as the main product in 48% yield.

GRAPHICAL ABSTRACT      

Fluorine-containing heterocycles: XVI. Reactions of tetrafluorobenzoyl isothiocyanate with hydrazines and their derivatives

Fluorinated derivatives of 4H-1,3-benzothiazin-4-one, [1,2,4]triazolo[4,3-a]pyrimidine, [1,2,4]triazolo[3,4-b][1,3]benzazoles, and 1,5-dihydro-1,2,4-triazole-5-thione were synthesized by addition of hydrazines and their derivatives to tetrafluorobenzoyl isothiocyanate, followed by cyclization of intermediate thiosemicarbazides.     

Thiylation of Functionalized Electrophiles with Sulfur in Basic Reductive Systems

Functionalized electrophiles, specifically acetyl chloride, benzoyl chloride, chloroacetylchloride, benzenesulfonyl chloride, and N,N,4-trichlorobenzenesulfonamide, were brought into reaction with sulfur in the systems hydrazine hydrate-NaOH and sodium sulfide-water-ethanol. The efficiencies of these systems were compared. The reaction of chloroacetyl chloride with sulfur in the system hydrazine hydrate-base afforded new types of polymeric compounds, poly[(diacylhydrazine)polysulfides]. The reaction mechanisms were discussed.     

The Reactions of Dialkyl Phosphites and Phosphine Oxides with Iodosylbenzene

The reaction of iodosylbenzene with >P(O)H type of acids (dialkyl phosphites, secondary phosphine oxides) was studied. The acids of >P(O)H type add to iodosylbenzene to yield intermediate 6 which in the aprotic solvents yields oxidation products, it means >P(O)OH acids and/or anhydride of >P(O)OP(O)< type. On the other hand if the reaction is performed in alcohol as a solvent in the presence of sodium alcoholate >P(O)OR ester is the major product.     

Reactions of Difunctional Electrophiles with Functionalized Aryllithium Compounds: Remarkable Chemoselectivity by Flash Chemistry

Flash chemistry using flow microreactors enables highly chemoselective reactions of difunctional electrophiles with functionalized aryllithium compounds by virtue of extremely fast micromixing. The approach serves as a powerful method for protecting‐group‐free synthesis using organolithium compounds and opens a new possibility in the synthesis of polyfunctional organic molecules.