Phosphinyl analogues of hydroxybupropion: (±)-2-aryl-3,3,5,5-tetramethyl-[1,4,2]-oxazaphosphinanes

Analogous structures in phosphinate series of hydroxybupropion 2, that is, (±)-2-aryl-3,3,5,5-tetramethyl-[1,4,2]-oxazaphosphinanes 8, are prepared according to a two step sequence: addition-cyclization reaction from methyl hypophosphite and oxazolidine 6, followed by a pallado-catalyzed arylation of P-H bond from oxazaphosphinane 7.     

A convenient synthesis and spatial structure of 2-aryl-2-oxo-2-phenylbenzo[e]-1,4,2-oxazaphosphinanes

Phosphorylation of 2-arylideneaminophenol with dichlorophenylphosphine in the presence of triethylamine and subsequent treatment with water led to stereoisomeric derivatives of 3-aryl-2-oxo-2-phenylbenzo[e]-1,4,2-oxazaphosphinanes, which were separated by column chromatography to the individual diastereomers. The structure of stereoisomers was established by NMR spectroscopy and X-ray crystallography.     

Configuration and conformation of 3,5-diphenyl-2-thiabicyclo[4.4.0]decane

The PMR spectra of 3,5-diphenyl-2-thiabicyclo[4.4.0]decane and its 4,6-dideutero derivative and S-oxide in the presence of Eu(dpm)₃ were studied. It was established that 3,5-diphenyl-2-thiabicyclo[4.4.0]decane has a cis,cis,cis configuration. The extremal spin-spin coupling constants (SSCC) constitute evidence for conformational rigidity of the investigated condensed system, which exists in the form of a puckered chair. The formation of the same cis,cis,cis isomer of 3,5-diphenyl-2-thiabicyclo[4.4.O]decane in the case of catalytic hydrogenation, disproportionation with trifluoroacetic acid, and ionic hydrogenation constitutes evidence for stereospecificity of the processes involving the reduction of the double bonds in 2,4-diphenyl-5,6-tetramethylene-6H-thiopyran.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1347–1350, October, 1981.     

Synthesis of 2-phenoxyl-2-oxo-1,4,2-oxazaphosphinanes from a three component reaction

Abstract

A one-pot synthetic strategy was developed for the synthesis of heterocyclic 1,4,2-oxazaphosphinanes via a three component Kabachnik-Fields reaction of 2-aminophenol, diphenyl H-phosphonate and carbonyl compounds. Through this newly developed method, 12 organophosphorus heterocycles and 2 related chrysin derivatives were synthesized with high yields. The target compounds were characterized by ¹H, ³¹P and 13C NMR and MS.     

First syntheses of 2-hydrogeno-2-oxo-1,4,2-oxazaphosphinanes via intramolecular esterification

Synthesis of 2-hydrogeno-2-oxo-1,4,2-oxazaphosphinanes via either intramolecular transesterification, using potassium tert-butylate as catalytic agent, or phosphinic acid esterification, is described for the first time.     

Diastereoselective addition of 2H-2-oxo-1,4,2-oxazaphosphinanes to aldehydes and imines

[reaction: see text] Diastereoselective additions of 2-hydrogeno-2-oxo-1,4,2-oxazaphosphinanes to aldehydes and imines are described. alpha,alpha'-Diaminophosphinic and alpha-amino-alpha'-hydroxyphosphinic derivatives were obtained with de's ranging from 24 to 90%.     

Pallado-catalysed P-arylations and P-vinylation of 2-hydrogeno-2-oxo-1,4,2-oxazaphosphinanes

A simple and effective preparation of 2-aryl- (or 2-vinyl)-1,4,2-oxazaphosphinanes, phosphorus analogues of aryl-morpholinols has been developed, involving palladium catalysed coupling of aryl (or vinyl)-halides with 2-H-1,4,2-oxazaphosphinane in presence of triethylamine. A deprotection step was also proposed to afford the corresponding P-aryl-α-aminobenzylphosphinic acid.     

Synthesis of 4-aryl-1,3-diphenyl-1,4,5,10-tetrahydropyrazolo-[3,4-b][1,5]benzodiazepines

A convenient method is proposed for the synthesis of the previously unknown 4-aryl-1,3-diphenyl-1,4,5,10-tetrahydropyrazolo[3,4-b][1,5]benzodiazepines by cyclocondensation of 5-(2-aminoanilino)-1,3-diphenylpyrazole with aromatic aldehydes. The reaction only takes place very selectively with aldehydes which contain electron acceptor substituents in the aryl fragment. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 913–918, June, 2006.     

Synthesis and antifungal activities of 3,5-diphenyl-7-amino-[1,3]-thiazolo[3,2-a]pyrimidine-6-nitrile derivatives

A series of novel 3,7-diphenyl-7-amino[1,3]-thiazolo[3,2-a]pyrimidine-6-nitrile derivatives 3 were synthesized by refluxing 2-amino-4-phenyl-1,3-thiazole 1 and arylidinemalononitrile 2 in propanol using NaOH as catalyst. Various synthesized products were characterized by ¹H NMR, mass spectrometry (MS), infrared (IR), and elemental analysis. Antifungal activities of the synthesized compounds were done by testing against Rhizoctonia solani and Drechslera orazae, two fungal pathogens causing diseases on rice crops.     

Synthesis and spectral characteristics of 2-aryl-6-methyl-and 2-aryl-6-benzyl-4,8a-diphenylperhydro[1,3,2]dioxaborinino[5,4-c]pyridines

Aryl-N-methyl-and aryl-N-benzyl-B-substituted 4,8a-diphenylperhydro[1,3,2]dioxaborinino[5,4-c]pyridines, which are representatives of a new class of bicyclic compounds containing four heteroatoms, were synthesized from N-methyl-and N-benzyl-3-(α-hydroxybenzyl)-4-phenyl-γ-piperidols by cyclocondensation with arylboronic acids. The ¹H NMR and mass spectra of these compounds were examined as well as mass spectra of previously obtained analogs. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1253–1259, August, 2008.     

Desulfurization reaction of cis-1,2-diphenyl-3-aryl-1,4,2-diazaphospholidin-5-thione-2-oxides utilizing an Ag+−H2O or ROH system

A desulfurization reaction of the title compounds, as cyclic substrates, utilizing an Ag⁺−H₂O or ROH system, is described in this article. The diastereoisomerism of ring-opening products and the possible reaction mechanism are also discussed. Themolecular structure of α-(3-phenylureido)-α-(2,4-dichlorophenyl)methylphenylphosphinic acid (4a) was determined by X-ray diffraction. © 1998 John Wiley & Sons, Inc. Heteroatom Chem 9: 585–590, 1998     

Chiral tetraoxacalix[2]arene[2]triazine-based organocatalysts for Enantioselective Aldol reactions

Novel efficient chiral tetraoxacalix[2]arene[2]triazine-based organocatalysts have been designed and synthesized from the reaction of tetraoxacalix[2]arene[2]triazine with R/S-phenylethylamine or R/S-1-naphthylethylamine for the Aldol reaction of acetone with aromatic aldehydes to furnish the Aldol adducts in 71–92% yields with excellent enantioselectivities (78–99%).     

Palladium-assisted multicomponent synthesis of 2-aryl-4-aminoquinolines and 2-aryl-4-amino[1,8]naphthyridines

A palladium-mediated multicomponent domino reaction leading to 2-aryl-4-amino-quinolines and 2-aryl-4-amino[1,8]naphthyridines is reported. The scope of the reaction was examined using carbon monoxide, two 2-ethynyl-arylamines, four aryl iodides, and 10 primary amines as substrates. The selection of the appropriate catalytic system was achieved testing several palladium/phosphine systems and overrides previously reported drawbacks associated with the use of primary amines in related reactions. Moreover several features concerning the role of both palladium [(0) and (II)] and phosphines are reported.     

Cyanoethylation of stereoisomeric 4-nitro-3,5-diphenyl-2-isoxazolines

Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, p. 1431, October, 1990.     

9,9-diphenyl-1,9,10,10a-tetrahydro-2H-phenaleno[1,9-bc]pyrans

Reaction between some naphtho[2,1-b]pyrans and 1,1-diphenylethene affords 9,9-diphenyl-1,9,10,10a-tetrahydro-2H-phenaleno[1,9-bc]pyrans.     

Formation of 3,5-diphenyl-2-thiabicyclo[4.4.0]dec-Δ1,6-ene under the conditions of the pummerer reaction and its structure

The Pummerer rearrangement was investigated in the case of 3,5-diphenyl-2-thiabicyclo [4.4.0]decane S-oxide. It is shown that, of the two possible isomers, this compound forms only 3,5-diphenyl-2-thiabicyclo[4.4.0]dec-^1,6-ene under the conditions of the Pummerer reaction; a secondary transformation, viz., disproportionation of the latter to 3,5-diphenyl-2-thiabicyclo[4.4.0]decane and 2,4-diphenyl-5, 6-tetramethylenethiopyrylium acetate, is observed. 3,5-Diphenyl-2-thiabicyclo[4.-4.0] dec-^1,6-ene was subjected to an x-ray diffraction study; it was proved unambiguously that the C₁=C₆ double bond has a length of 1.335 Å and that the dihydrothiopyran and cyclohexene rings have a distorted half-chair conformation: the dihedral angles between the phenyl rings and the planar fragment of the heteroring are 76.8 and 93.2 °C.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1056–1059, August, 1980.     

Synthesis and nmr study of 7-aryl-1,2,4-triazolo-[1,5-a]-1, 3,5-triazines

The reactionof N-(1,2,4)-triazol-5-yl)amidines with ethyl orthoformate is a convenient method for the fusion of a triazine ring to the triazole ring. An NMR study showed that the heterocyclic compounds obtained are 7-aryl-1,2,4-triazolo-[1,5- a]-1,3,5-triazines.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2386–2388, October, 1989.