L. M. Abdrakhmanova

The Molecular Design of “Carcass”-Type Phosphoranes, Based on the Reaction of P(III)-Cyclic Derivatives and Unsaturated Activated Compounds

Abstract The methodology for the synthesis of carcass-type (cage-like type) phosphoranes was developed, which allows us to obtain the products of the given structure with a high regio- and stereoselectivity in the result of cascade processes.

A New Approach to The Synthesis of Phosphoranes Based on the Reaction of Benzo[d]-1,3,2-Dioxaphospholes, Having β- or γ-Unsaturated Group in a Substituent, with Compounds Containing Multiple Bonds

We developed a new approach to the synthesis of phosphoranes and carba phosphatranes on the basis of the reaction of benzo[d]-1,3,2-dioxaphospholes, having β- or γ-unsaturated group in a substituent, with such compounds containing multiple bonds, such as hexafluoroacetone, chloral, and diethylacetylenedicarboxylate.

Synthesis and steric structure of 3′,3′,5′-trimethyl-7′,7′-bis(trifluoromethyl)spiro[1,3,2-benzodioxaphosphole-2,1′-[2,6,8]trioxa[1λ5]phosphabicyclo[3.2.1]octane] and 3′,5′-dimethyl-7′,7′-bis(trifluoromethyl)spiro[1,3,2-benzodioxaphosphole-2,1′-[2,6,8]trioxa[1λ5]phosphabicyclo[3.2.1]oct[3]ene]

Reactions of hexafluoroacetone with 4-(1,3,2-benzodioxaphosphol-2-yloxy)-4-methylpentan-2-one and 4-(1,3,2-benzodioxaphosphol-2-yloxy)pent-3-en-2-one afforded cage spiro phosphoranes with a phosphorus-carbon bond, 3′,3′,5′-trimethyl-7′,7′-bis(trifluoromethyl)spiro[1,3,2-benzodioxaphosphole-2,1′-[2,6,8]-trioxa[1λ5]phosphabicyclo[3.2.1]octane] and 3′,5′-dimethyl-7′,7′-bis(trifluoromethyl)spiro[1,3,2-benzodioxaphosphole-2,1′-[2,6,8]trioxa[1λ5]phosphabicyclo[3.2.1]oct[3]ene], whose structure was determined by X-ray analysis.

Caged phosphorane with P-C bond based on chloral and 4,5-dimethyl-2-(2-oxo-1,2-diphenylethoxy)-1,3,2-dioxaphospholane

The key methods of caged phosphoranes synthesis are analyzed. Reaction of 4,5-dimethyl-2-(2-oxo-1,2-diphenylethoxy)-1,3,2-dioxaphospholane (prepared from the meso-form of 2,3-butanediol) with chloral has yielded the caged phosphorane containing a phosphorus-carbon bond: 1,1-(1,2-dimethylethylenedioxy)-3,4-diphenyl-6-trichloromethyl-2,5,7,1-trioxaphosphabicyclo[2.2.11,4]heptane; spatial structure of the product has been elucidated with X-ray diffraction analysis.

Caged C-P phosphoranes based on 2-(2-methyl-4-oxopent-2-yloxy)- and 2-[2-(methylcarbonyl)-1-phenoxy]-1,3,2-benzodioxaphospholes and diethyl mesoxalate

Cascade reactions of 2-(2-methyl-4-oxopent-2-yloxy)- and 2-[2-(methylcarbonyl)-1-phenoxy]-1,3,2-benzodioxaphospholes with diethyl mesoxalate yield caged phosphoranes containing a phosphoruscarbon bond: 7,7-bis(ethoxycarbonyl)-3,3,5-trimethyl-1,1-phenylenedioxy- and 7,7-bis(ethoxycarbonyl)-5-methyl-1,1-phenylenedioxy-3,4-benzo-2,6,8,1λ5-trioxaphosphabicyclo[3.2.11.5]octanes. Spatial structure of latter product has been determined by X-ray diffraction analysis.

Reaction of Li/Cl phosphinidenoid complexes with a phosphite substituted ketone: access to complexes with a novel mixed-valence polycyclic P,C-ligand system†‡

Reaction of Li/Cl phosphinidenoid pentacarbonyltungsten(0) complexes 2a,b (R = CH(SiMe3)2, Cp*) with bifunctional phosphite-substituted ketone 3 yielded tungsten complexes 4a,b having a novel mixed-valence polycyclic P,C-cage ligand with a P–P bond. DFT calculations provide insight into an unusual product formation pathway.

Special features of reaction of 2-(5-methyl-2-phenyl-2H-1,2,3-diazaphosphol-4-yl)-4H-benzo[d]-1,3,2-dioxaphosphorin-4-one with diethyl mesoxalate

Mixed anhydrides of salicylic and phosphoric (phosphonic) acids, salicylphosphites (phosphonites), are convenient and available reagents for the synthesis of derivatives of tetraand pentacoordinate phosphorus owing to the presence of the energy-rich Р–О bond [1]. Introducing to the atom of the tricoordinate phosphorus an additional diazaphosphol fragment containing a bicoordinate phosphorus could have both affected the regiochemistry of reactions of the salicylphosphites with activated carbonyl compounds and led to the formation of new reaction products. In this study by the reaction of previously described [2] 4-(dichlorophosphino)-5-methyl-2-phenyl-2H1,2,3-diaza phosphol with bis(О-trimethylsilyl) derivative of salicylic acid we prepared for the fi rst time 2-(5-methyl-2-phenyl-2H-1,2,3-diazaphosphol-4-yl)4H-benzo[d]-1,3,2-dioxaphosphorin-4-one (I) containing two phosphorus atoms of different coordination at a carbon atom (P=C–P) and investigated its reaction with diethyl mesoxalate. Common phosphorus derivatives of hydroxycarboxylic acids react with this compound forming phosphoranes and leaving intact the anhydride Р–О bond [3]; the introduction to the atom of the tricoordinate phosphorus of an isocyanate group leads to the formation of products of bicyclononane structure [4]. Although the molecule of compound I contains a reactive bicoordinate P atom, the reaction occurs exclusively at the tricoordinate P atom resulting in the formation of 2-(5-methyl-2-phenyl-2H-1,2,3-diazaphosphol-4-yl)2,5-dioxo-4,4-bis(diethyldicarbonyl)benzo[2,3-f]-1,3,2dioxaphosphepine (II). Thus 5-methyl-2-phenyl-2H1,2,3-diazaphosphol-4-yl substituent apparently owing to its electronic and steric effects directed the reaction to the path uncharacteristic of the diethyl mesoxalate involving

Reaction of ethyl trifluoropyruvate with 2-(5-Methyl-2-phenyl-2H-1,2,3-diazaphosphol-4-yl)-4H-benzo[d]-1,3,2-dioxaphosphorin-4-one. Effect of exocyclic substituent on chemoselectivity

Benzo[d]-1,3,2-dioxaphosphorin-4-ones (P-phosphorrylated cyclic derivatives of salicylic acid), containing a nucleophilic phosphorus atom and electrophilic endocyclic carbonyl group, exhibit a specific reactivity. They react readily to increase the ring to sevenmembered one by the action of activated systems with multiple bonds [1–6]. Introduction to the phosphorus atom of the benzo[d]-1,3,2-dioxaphosphorin-4-one an exocyclic substituent, the λσ-diazaphosphol fragment containing the P atom, could change the direction of the interaction with such activated unsaturated systems as carbonyl compounds. Indeed, it appears that the weak-acceptor and bulky diazaphosphol moiety in the compound I leads to a change of the reaction direction with ethyl trifluoropyruvate. In contrast to the ordinary derivatives of benzo[d]1,3,2-dioxaphosphorin-4-one [7], here predominates (>90%) the formation of a (Р–С → Р–ОС)-regrouping product, the 1,3,2-dioxaphosphepin derivative II involving a dioxaphosphorine fragment only. The trifluoropyruvate ester contains a prochiral carbonyl group, which is the source of the second chiral center (C), causing the formation of two diastereomers (55:45) of the reaction product II, whose structure was established by the NMR and mass spectrometry. The H, С–{H}, Р–{H} NMR spectra of the compound II purified from the volatile impurities contain a double set of signals that can not be attributed to one or other diastereomers due to their close arrangement. The minor reaction direction (<8%) is the formation of a pentacoordinated phosphorus atom derivative III, whose signals in the Р–{H} NMR spectrum are: –32.3 d, –34.1 d (5:1) (P), 254.0 br.d (P) (JРСР 87.2–87.3 Hz).

Synthesis and Some Properties of 2-(5-Methyl-2-Phenyl-2H-1,2,3-Diazaphosphol-4-yl)-4H-Benzo[d]-1,3,2-Dioxaphosphorin-4-One

Abstract 2-(5-Methyl-2-phenyl-2Н-1,2,3-diazaphosphol-4-yl)-4H-benzo[d]-1,3,2-dioxaphosphorin-4-one 1 readily reacts with hexafluoroacetone, mesoxalic acid diethyl ester, trifluoropyruvic acid ethyl ester and chloral to give 2-(5-methyl-2-phenyl-2H-1,2,3-dizaphosphole-4-yl)-derivatives of 1,3,2- and 1,4,2-dioxaphosphepines. GRAPHICAL ABSTRACT

Cycloexpansion Reactions in Benzo[e]-1,3,2-diheterophosphorin-4-ones and 4-Oxo-1,3,2-dioxaphospholanes

Abstract The peculiarities of the reactions of 2-R-benzo[d]-1,3,2-dioxaphosphorin-4-ones, 2-R-naphtho[d]-1,3,2-dioxaphosphorin-4-ones, 2-R-8-azabenzo[e]-1,3,2-dioxaphosphorin-4-ones, and 2-R-1,3,2-dioxaphospholan-4-ones with unsaturated compounds are summarized in the review. The reactions proceed in the mild conditions and lead to the formation of the seven- and six-membered heterocycles 1,3,2-dioxa-, 1,3,2-oxaza-, 1,4,2-dioxa-, and 1,4,2-oxazaphosphepines and 1,3,2- and 1,4,2-dioxaphosphorinanes with a high regio- and stereoselectivity. The hydrolysis and thermolysis of the some benzophosphepine derivatives leads to the substituted fluorinated ketones and various nonphosphorus heterocycles.