Isothiocyanatochloromethylphosphonates and Phosphinates – Versatile Synthones for Obtaining of S (Se), N,P–Containing Heterocycles

Abstract

Isothiocyanatochloromethyl(thio)phosphonates and (thio)-phosphinates 1 (X=O, S; R¹ = OPh, CH₂Cl, NCS; R² = H, Cl have been found to be convenient starting material for synthesis of a variety of S (Se), N, P-containing cyclic compounds. They react with different proton containing nucleophiles in the presence of a base with formation of saturated 2 and unsaturated 3 five membered phosphacyclanes. Diisothiocyanatodichloromethylphosphonates 1 (R¹ = NCS, R² =Cl) produce with amines and thiols appropriate bicyclic compounds 4.     

A Novel Method for Synthesizing 6-Chloro and 6-Methoxypurinenucleoside

Starting from tetraacetylribofuranose (Ⅰ) and 6-chloropurine (Ⅲ), in the presence ofp-toluenesulfonic acid as catalyst, the intermediate 2',3',5'-tri-O-acetyl-6-chloropurine nucleoside (Ⅲ) was synthesized for the first time under microwave irradiation in the yield of 80.1%. The title compounds 6-chloro-9-β-D-purinenucleoside (Ⅳ) and 6-methoxy9-β-D-purinenucleoside (Ⅴ) were easily obtained by treatment the intermediate (Ⅲ) with NH3/CH3OH and Na2CO3/CH3OH in the yields of 78.8% and 76.9%, respectively. Structures of Ⅳ and Ⅴ have been identified by 1H NMRand elementary analysis. The optimal conditions for condensation were as follows: n(Ⅰ): n(Ⅱ)= 1: 1, m(TsOH):m(6-chloropurine)=3 × 10-2, microwave irradiation at 595 W for 4.5 min, at 462 W for 1 min, at 119 W for 0.5 min;aminolysis condition for Ⅳ: room temperature for 5 min; alkaline hydrolysis conditions for Ⅴ: reflux for 5 h.     

Synthesis of Novel Dendrimers Containing Amino Acids and Peptides

Dendrimers are known for their well-defined, regular, highly branched architectures with a large number of functional groups1. Recently, dendrimers have been widely researched in different fields, such as molecular light havesting, catalysts, liquid cryst…     

Reaction of Acids and Diacids with Aroxy(alcoxy)sulfonyl Isocyanates: Synthesis of N-Acylsulfamates,Disulfamates, and N,N′-Disulfonylureas

Reaction of carboxylic acids with aroxy(alcoxy)sulfonylisocyanates allowed the preparation of the corresponding aroxy(alcoxy) N-acylsulfamates. With succinic diacid, the same reaction yielded the corresponding N, N′-diacylsulfamates, whereas the N, N′-disulfonylureas were obtained by reaction of maleic or fumaric diacids.     

A Novel Method for Synthesizing 6-Chloro and 6-Methoxy purinenucleoside

Starting from tetraacetylribofuranose and 6-chloropurine, in the presence of p-toluenesulfonic acid as catalyst, the intermediate 2′,3′,5′-tri-O-acetyl-6-chloropurinenucleoside was synthesized for the first time under microwave irradiation. The title compound 6-chloro-9-β -D-purinenucleoside (IV) and 6-methoxy-9-β-D-purinenucleoside (V) was easily obtained by treatment of the intermediate (III) with Na2CO3 in CH3OH solution refluxing for 8min and 2hr respectively. Cl AcO OAc…     

N‐Methylation of Nitrogen‐Containing Heterocycles with Dimethyl Carbonate

Reactivity of dimethyl carbonate, the environmentally friendly reagent, as methylating agent for nitrogen‐containing heterocyclic compounds has been studied. Reactions of imidazole, pyrazole, pyrrole, morpholine, and piperazine with dimethyl carbonate to afford N‐methylated products were reported. The reactions were carried out with neither catalyst nor solvent at a temperature range of 110–170°C under atmospheric pressure.     

New Method of Synthesizing N‐Alkoxycarbonyl‐N‐arylamide with Triphosgene

N‐Chloroformyl‐N‐arylcarbamate, the key intermediate for the synthesis of some excellent pesticides, was synthesized through a new method with triphosgene instead of toxic phosgene. It cannot be obtained through the traditional method using triethylamine as a nucleophile. When triethylamine was replaced by a stronger base, sodium hydride, the product was obtained in good yield.     

Coupling Reaction of Organoboronic Acids with Chloropyrimidines and Trichlorotriazine

Pd-catalyzed cross-coupling reactions of chloropyrimidirtes with alkenylboronic acids readily proceed to give the corresponding alkenylpyrimidines in high to excellent yields. The coupling reaction of 2,4-dichloropyrimidine or 2,4,6-trichloropyrimidine with one equivalent of alkenylboronic acid occurred more easily on 4-position than on 2-position, which implied that the reaction is highly regioselective. The reaction is stereospecific since the configuration of C=C remained intact. The preliminary study on the cross-coupling reactions of 2,4,6-trichlorotriazine with one equivalent of arylboronic acids showed that the reactions afforded the monosubstituted triazines in moderate yields. The effect of steric hindrance of the substitutents on the reactions was found.     

A Novel Method for Synthesizing 4,4′-Bis(hydroxymethyl)-2,2′-bipyridine

IntroductionSince C. W. Tang firstly reported theelectroluminescence of 8- hydroxyquinolinealuminium[1] ,much attention has been paid to themetal complexes as electro- luminescent materials.Based on a series of experimental data,it has beenknown that the electroluminescence of metalcomplexes with heterocyclic ligands containing Nand O elements mainly results from the tripletstatetransition.For some transitional metal complexes,there exist the transitions from metal to ligand( MLCT) at thei…     

Reaction of Polyfluorinated β-Diimines with Ketones. A Novel Method for the Synthesis of Fluorinated Pyridines

Reaction of polyfluorinated -diimines with ketones gave polyfluorinated pyridines     

A Novel and Facile Method to Synthesize (R)‐ and (S)‐2‐methylpiperazine

Abstract

A concise and efficient synthesis of (R)‐ and (S)‐2‐methylpiperazine in only five steps from (D)‐ and (L)‐alanine is described. The key step is reaction of benzylamine with a bifunctional molecule to build a six‐membered ring.     

Analysis of Lanthanide π-Complexes Containing N,P, and As Atoms

A sampling comprising 92 LnC _n H _m Q _k -complexes (Ln = Sc, Y, or lanthanides; Q = N, P, As) was used to analyze the influence of the nature, the oxidation state, and the coordination number of the central Ln atom and the nature of the Q atom on the parameters of the lanthanide action area. The effect of steric factors on the stability of complex groups and on the presence (or absence) of agostic interactions in the structures of these complexes was studied. A number of crystal structure features found previously for lanthanide -complexes of a different stoichiometric composition was confirmed for the structures of the given complexes.     

Reaction of N,N′-Methylenebis(trifluoromethanesulfonamide) with Styrene under Oxidative Conditions

Russian Journal of Organic Chemistry - The reaction of N,N′-methylenebis(trifluoromethanesulfonamide) with styrene in the oxidative system t-BuOCl/NaI affords triflamide,...     

Synthesis, Structure and Biological Activities of Novel Triazole Compounds Containing N,N-Dialkyldithiocarbamate Moiety

Introduction As an important type of fungicides, triazole compounds are highly efficient, low poisonous and inward absorbent.1-3 At present, the studies on triazole derivatives are mainly concentrated on compounds with triazole as the only active group. The report of triazole compounds that contain both triazole group and other active group in a single molecule has rarely been found. Dialkyl-substituted dithiocarbamate salts have also shown interesting biological effects.4 N,N-Dialkyldithio-…     

Reaction of Lewisite-1 with Alcohols,Diols, and Thiols in Water—A Simple Method of Derivatization of Thiodiglycol

Reaction of 2-chlorovinyldichloroarsine (Lewisite-1) with alcohols, thiols, diols, and hydroxy thiols in water at 40°C has been examined. The expected derivatization products, dialkyl 2-chlorovinylarsonites or corresponding arsonodithiolites, were obtained with alcohols and thiols, whereas reactions with bifunctional diols and hydroxythiols produced analogous cyclic esters. All derivatives may be easily detected using gas chromatography. This reaction was found useful to easily transform bis(2-hydroxyethyl) sulfide (thiodiglycol), a sulfur mustard decomposition product, to a stable eight-membered cyclic arsonite derivative. After extraction with dichloromethane, the derivative may be easily and selectively detected using GC/MS at a 100 ppb level thiodiglycol content in water matrices, eliminating tedious evaporation of water and then silylation. This method may be applied to analyze Chemical Weapons Convention related environmental water samples.     

Reaction of Ph3P(SCN)2 with Further Orthohydroxy Carboxylic Acid Systems,Including Substituted β-Keto Acids: Synthesis of Novel 2-Thio-1,3-oxazines and Their Subsequent Transformation with Amines

We now report the first reaction of Ph₃P(SCN)₂ with 4,6-dihydroxy-5-methylisophthalic acid to give 10-methyl-2,8-dithio-1,3-oxazino-1,3-benzoxazine-4,6-dione. Also, the enol tautomer has been utilized in the reaction of β-keto acids with Ph₃P(SCN)₂ to give novel 2-thio-1,3-oxazines. Subsequent reaction of the 2-thio-1,3-oxazines with benzylamine resulted in opening of the oxazine ring and gave novel dibenzylamino-enamides, which could be cyclized to thiouracils. The reaction of 2-thio-1,3-oxazines with morpholine at low temperature led to the production of unstable 2-Mercapto-2-morpholino-1,3-oxazines. 2-Mercapto-2-morpholin-4-yl-2,3,5,6,7,8-hexahydro-4H-1,3-benzoxazin-4-one was observed to lose H₂S at room temperature to give 2-morpholin-4-yl-5,6,7,8-tetrahydro-4H-1,3-benzoxazin-4-one, which was subsequently tested and found to exhibit some antiplatelet activity.     

Synthesis and Reaction of 4-Methyl-3,4-epithiotetrahydropyran with α-Amino Acids

4-Methyl-3,4-epithiotetrahydropyran was synthesized by the recyclization of 4-methyl-3,4-epoxytetrahydropyran by the action of thiourea. The product reacts with -amino acids in an alkaline medium with regioselective opening of the thiirane ring at the least substituted carbon atom.     

Synthesis and Characterization of Novel Orange-emitting Iridium(III) Complexes with Diphenylquinoline Ligands Containing Fluorinated Substituent

Recently, the iridium complexes as phosphorescent emitter in organic light-emitting diodes (OLEDs) have attracted much attention since the realization of a high efficiency OLED device based on the complex fac tris(2-phenylpyridine)iridium [Ir(ppy)3]1-4. T…     

A Novel Method for the Synthesis of High Hindered Iminoesters by the Reaction of Decomposition of Phenyldiazoacetate in the Presence of Rh2(OAc)4 with Arylamines and DEAD

It is well known that iminoesters were condensed by ketoesters with amines, but the procedure to ketoesters require harsh reaction conditions and multi steps. Herein we report a mild and practical one-step approach for the synthesis of iminoesters, especially for the high steric hindered iminoesters. Decomposition of phenyl diazoacetate catalyzed by rhodium acetate with amines to give N-H insertion product has been reported.     

Micellar Mediated Halodecarboxylation of α,β‐Unsaturated Aliphatic and Aromatic Carboxylic Acids—A Novel Green Hunsdiecker–Borodin Reaction

A Novel Hunsdiecker‐Borodin reaction (HBR) has been carried out efficiently with α,β‐unsaturated aliphatic and aromatic carboxylic acids by using N‐halo succinimides such as N‐chloro succinimide (NCS), N‐bromo succinimide (NBS), and N‐iodo succinimide (NIS) under micellar media. The reaction with α,β‐unsaturated aromatic carboxylic acids afforded β‐halo styrenes in excellent yield while α,β‐unsaturated aliphatic carboxylic acids underwent decarboxylation and to give corresponding halo derivatives. The reactions are dramatically accelerated in micellar media. This procedure works efficiently in CTAB (cetyl trimethyl ammonium bromide), SDS (sodium dodecyl sulfate), and TX (Triton‐X‐100) media under stirred conditions at room temperature. At reflux temperatures the yield of reaction products were further enhanced from good to excellent.