Hexamethylphosphorous triamide-Dialkyl

In an analogous manner the enantiomeric unsaturated bicyclic lactam 11 was transformed via conjugate addition of dimethyl 1,3-propanedioate (sodium amide/hexamethylphosphoric triamide) and subsequent alkylation with (bromomethyl)benzene to give the dialkylated product 12 in 20% yield12. 

Tricyclic lactams, such as exo- and c r/n-3a,4,7,7a-tetrahydro-4,7-methano-2-phenyl-1 //-isoin-dolc-1,3(2//)-dione (4), have been transformed into their dianions by treatment with slightly more than two equivalents of lithium diisopropylamide in tetrahydrofuran, sometimes with hexamethylphosphoric triamide as cosolvent. Alkylation with iodomethane or the bifunctional 1,4-dibromobutane leads to dialkylated products2. 

Dialkyl and diaryl ditellurium compounds are easily reduced to tellurols and tellurolates. Alkali metals in liquid ammonia or in an inert organic solvent, sodium borohydride in methanol, ethanol, alcohol/benzene, THF, DMF, or in a basic aqueous medium, lithium aluminum hydride in dioxane or THF/hexamethylphosphoric triamide, and thiourea dioxide in THF/50% aqueous sodium hydroxide have been used as reducing agents (p. 164). The tellurolates are easily oxidized in air. For this reason they are almost always used in situ. 

Alkanetellurolates, that can be obtained from an organic lithium compound or a Grignard reagent and tellurium, are oxidized to dialkyl ditellurium compounds on contact with air. Di-t-butyl ditellurium, that is difficult to prepare by other routes, was obtained by this method in excellent yield The reaction of t-butyl magnesium chloride with tellurium proceeded in THF solution only in the presence of hexamethylphosphoric triamide. ... 

Alkyl vinyl tellurium compunds were obtained when tellurium was reacted with acetylene in the presence of an alkyl halide in a system consisting of potassium hydroxide, tin(II) chloride, water, and hexamethylphosphoric triamide . Divinyl tellurium (53-60% yield) and dialkyl telluriums (4-12% yield) were also formed in these reactions. 

Abstraction of positive halogen by trivalent phosphorus compounds represents an expeditious route for the synthesis of dialkyl l-(trimethylsilyl)methylphosphonates. Thus, treatment of diethyl trichloromethylphosphonate with hexamethylphosphorous triamide (HMPT) in the presence of McjSiCl in CgHg at room temperature affords diethyl l-(trimethylsilyl)-l,l-dichloromethylphos-phonate in 90% yield. Similarly, CCI4 and CICI3 have been reacted with trimethylsilylmethyl dialkyl phosphites. ... 

Mixed carbonates. Mixed carbonates can be prepared by the reaction of alcohols with dialkyl azodicarboxylates and hexamethylphosphorous triamide ... 

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