Sereoselective Addition of Benzaldehyde N,N-Dimethyl-Hydrazone to 2-RfO-4-Oxo-5,6-Benzo-1,3,2-Dioxaphosphorinanes. The Spatial Structure of 2-Pentafluorophenoxy-4-Dimethylamino-2,5-Dioxo-3-Phenyl-6,7-Benzo-1,4,2-Oxazaphosphepine

Abstract

[3+2]-Cycloaddition of N,N-dimethylhydrazone benzaldehyde (I) to 2-R_FO-4-oxo-5,6-benzo-l,3,2-dioxaphosphorinanes (II) yields the new heterocycle - 2-R_FO-4-Me₂N-2,5-dioxo-3-phenyl-6,7-benzo- 1,4,2-dioxaphosphepine (III) [R_F = C₆F₅, CH(CF₃)₂) with high stereoselectivity (above 94%). The reaction is likely to involve the initial interaction of nitrogen as a nucleophile with wbonyl carbon as an electrophile. The hydrolysis of (III) leads to phosphonic acid (IV) (OR_F = OH).     

Reactions of 2-Alkoxy-4-oxo-5,6-benzo- 1,3,2-dioxaphosphorinanes with Imines. Synthesis and Steric Structure of 6,7-Benzo-1,4,2-oxazaphosphepine Derivatives

2-Alkoxy-4-oxo-5,6-benzo-1,3,2-dioxaphosphorinanes containing an electron-withdrawing fluorinated exocyclic substituent at the P atom react with aromatic aldimines to give 6,7-benzo-1,4,2-oxaza- phosphepines with a high regio- and stereoselectivity. The major diastereomers were isolated, and their configuration was determined by single crystal X-ray diffraction.     

Reaction of 4-Oxo-5,6-benzo-1,3,2-dioxaphosphinin-2-yl Isocyanate with Dialkyl Arylcarbonylphosphonates

Russian Journal of General Chemistry -     

Reaction of 2-Tetrafluoropropoxy-5,6-benzo-1,3,2-dioxaphosphorinan-4-one with Pyruvonitrile

The reaction of pyruvonitrile with 2-tetrafluoropropoxy-5,6-benzo-1,3,2-dioxaphosphorinan-4-one results mainly in the enlargement of the starting heteroring to form 4-cyano-4-methyl-2-tetrafluoropropoxy-6,7-benzo-1,3,2⁵-dioxaphosphepin-5-one 2-oxide as a mixture of two diastereomers (14:1) along with minor amounts of 3-cyano-3-methyl-2-tetrafluoropropoxy-6,7-benzo-1,4,2⁵-dioxaphosphepin-5-one 2-oxide.     

Synthesis and Spatial Structure of 2,5-Dioxo-4-Dialkoxy-Phosphoryl-4-Aryl-6,7-Benzo-1,3,2-Dioxaphosphepines

Abstract

Phosphorus (111) containing dcrivatives of salicylic acid easily react with carbonyl compounds with formation of cycloexpansion products - 1,3,2- or 1,4,2-dioxaphosphepines. For the first time we have shown that dialkyl-l-oxólkylphosphonates react with 2-R-4-oxo-5,5-benzo-1,3,2-dioxaphosphorinanes and yield 1,3,2-dioxaphosphepines (I) with high stereoselectivity. The configuration of the preferable diastereoisomer (IId) has been determined by X-ray analysis. The hydrolysis of compounds (IIa-c) leads to formation of 2-hydroxy-2-oxo-1,3,2-dioxaphosphepines (III). The structure of phosphepine (IIIb) in crystal is shown on the figure. The work is supported by the Leading Scientific School Foundation of Russia (grant N 96-15-97330) and the Russian Foundation for Basic Research (grant N 98-03-33266).     

Quantum-Chemical Investigation of Reaction Mechanism of 2-R-4-Oxo-5,6-Benzo-1,3,2-Dioxaphosphorinanes with Chloral and Fluoral

Abstract

Reaction of 2-R-4-oxo-5,6-benzo-1,3,2-dioxaphosphorinanes I with chloral leading to formation of seven-membered heterocycles - 1,4,2-dioxaphosphepines is characterized by the high degree of stereoselectivity. We investigated the model reactions of 2-R-4-oxo-1,3,-dioxaphosphorin-5-enes with CX₃CHO by PM3 and ab initio methods in STO-3G, 3-21G, 6-31G*, MP2/6-31G* basis set and also DFT method (B3LYP).     

Synthesis and Spatial Structure of the Derivatives of 2,5-Dioxo-3,3-Bis(Trifluoromethyl)-6,7-Benzo-1,4,2-and 2,5-Dioxo-4,4-Bis(Trifluoromethyl)-6,7-Benzo-1,3,2-Oxazaphosphepines

Abstract

Hexafluoroacetone imine easily interacts with compounds (I, R = OMe, OCH₂CF₂CHF₂, NEt₂, Ph) in two directions unlike hexafluoroacttone and gives 1,4,2-oxazaphosphepines (II) (pathway I) or 1,3,2-oxszaphosphepines (III) (pathway 2). The compound (II) (R = NEt₂) lightly hydrolyzes to yield the salt (IV). The structure of heterocycles II-IV) has been confirmed by X-ray analysis (see fig. I, II, R = OMe; fig. 2, IV). The detail structural peculiarities of the compounds am discussed.     

Reaction of 2-[N,N-bis(Trimethylsilyl)]amino-4,5-benzo-1,3,2-dioxaphospholane with carboxylic acid halides

Conclusion The reaction of 2-[N,N-bis(trimethylsilyl)]amino-4,5-benzo-1,3,2-dioxaphospholane with acetyl and benzoyl chlorides leads to the formation of silicon-containing diazadiphospheti-dines.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 939–940, April, 1986.     

Conformational analysis of 2-phenyl-2-oxo-5,6-benzo-1,3,2-dioxaphosphepine with data from vibrational spectroscopy,dipole moments,and the kerr effect

2-Phenyl-2-oxo-5,6-benzo-1,3,2-dioxaphosphepine exists in a melt and solutions in polar solvents as a three-component equilibrium of two chair forms (C) with axial and equatorial arrangement of the phenyl group and the twist-boat form (TB) with a pseudoequatorial position of the phenyl substituent, a-C e-C e-TB. The two-component equilibrium e-C e-TB is observed in nonpolar solvents. The e-TB conformation occurs in the crystalline state. The dipole moment of the P=O groups is 3.5 D. The angle of rotation of the plane of the phenyl group with respect to the P=O bond in the e-TB conformation was 54 or 129.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1039–1043, May, 1991.     

Reaction of 2-substituted 4-oxo-5, 6-benzo-1, 3, 2-dioxaphosphorinanes with ethyl pyruvate

The reaction of 2-substituted 4-oxo-5, 6-benzo-1, 3, 2-dioxaphosphorinanes with ethyl pyruvate affords ring-expansion products, i.e., diastereomeric 2-substituted 2, 5-dioxo-6, 7benzo-1, 3, 2-dioxaphosphepanes.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 565–567, March, 1993.The authors are grateful to Ye.I.Gol'dfarb for recording the 31_P-(1_H) NMR spectra.     

Reaction of ketenes with N,N-disubstituted α-aminomethyleneketones. XVI. Synthesis of N,N-disubstituted 4-amino-5,6-tetramethylene-3-phenyl-2-pyranones

1,4-Cycloaddition of phenylchloroketene (prepared in situ from α-chlorophenylacetyl chloride and triethyl-amine) to a number of N,N-disubstituted (E)-2-aminomethylenecyclohexanones gave the corresponding adducts, namely N,N-disubstituted 4-amino-3-chloro-3,4,5,6,7,8-hexahydro-2H-1-benzopyran-2-ones III in the case of aliphatic N,N-disubstitution or aromatic N-monosubstitution. Purification of III was possible only in the case of IIIh (NR₂ = NMePh), therefore they were dehydrochlorinated in situ with DBN to give the title compounds in moderate overall yields.     

The Reaction of 4-Oxo-4H-[1]benzopyran-3-carbaldehyde with 1,2-Benzenediamine. X-Ray Structure Analysis of the Reaction Product

The reaction product of 4-oxo-4H-[1]benzopyran-3-carbaldehyde and 1,2-benzenediamine is 1,8-dihydro-6,13-bis(2-hydroxybenzoyl)dibenzo[b,i]-1,4,8,11-tetraazacyclotetradeca-4,6,11,13-tetraene ( 1 ), and its dehydrogenation product is 3-(2-benzimidazolyl)-4H-[1]benzopyran-4-one ( 2 ) as shown by X-ray structure analysis confirming our earlier report.     

Reaction of 2-dimethylaminomethylene-1,3-diones with dinucleophiles. V. Synthesis of 5-acyl-1,2-dihydro-2-oxo-3-pyridinecarbonitriles and 1,2,5,6,7,8-hexahydro-2,5-dioxo-3-quinolinecarboxamides

The reaction of open-chain sym-2-dimethylaminomethylene-1,3-diones Ia-d with sodium cyanoacetamide gave, generally in good yields, 6-substituted 5-acyl-1,2-dihydro-2-oxo-3-pyridinecarbonitriles IIa-d, whereas cyclohexane sym-2-dimethylaminomethylene-1,3-diones Ie-h afforded in general a mixture of 1,2,5,6,7,8-hexahydro-2,5-dioxo-3-quinolinecarbonitriles and 5,6,7,8-tetrahydro-2,5-dioxo-2H-1-benzopyran-3-carboxamides, the latter being isolated in two cases. The reaction of Ie-h with cyanoacetamide in refluxing anhydrous ethanol gave 1,2,5,6,7,8-hexahydro-2,5-dioxo-3-quinolinecarboxamides IIIe-h in excellent yields, whereas Ia-d did not react with the exception of Ia which afforded in good yield 3-pyridinecarboxamide IlIa. Other 3-pyridine-carboxamides were obtained by partial hydrolysis of nitriles IIb,d. 3-Pyridine and 3-quinoline carboxamides were hydrolyzed in satisfactory yields with hydrochloric acid to the corresponding carboxylic acids, which were decarboxylated in good yields to 5-acyl-2(1H)-pyridinones and 7,8-dihydro-2,5(1H,6H)-quinolinediones, respectively, by reflux in quinoline containing a catalytic amount of copper powder.     

3-Benzoylquinoxalin-2(1H)-one in the Kostanecki-Robinson Reaction. Synthesis and Structure of 2-Oxo-4-phenylpyrano[2,3-b]quinoxaline

3-Benzoylquinoxalin-2(1H)-one is cyclized with acetic anhydride in the presence of pyridine into 2-oxo-4-phenylpyrano[2,3-b]quinoxaline.