Hexamethylphosphoric triamide HMPA

Unreacted chloride remains at the end of the roaetion (with R2CuLi 15%, with RLi 40%) 1.5 equivalents of R2CuLi per equivalent of chloride givos 95% (. /)-2-undecene after 5 days at 25°. e A volumo of THF equal to that of the ether present was added after formation of the cuprate was complete. THF tetra-hydrofuran HMPA hexamethylphosphoric triamide EtaO diethyl ether DME 1,2-diinethoxyethane. 

Pic, pyridine-2-carboxylate HMPA, hexamethylphosphoric triamide OEP, octaethylporphyrin. 

A-Alkylation, -acylation and -sulfonation are also promoted by a polar solvent, such as HMPA (hexamethylphosphoric triamide).This acts to solvate the ions (promoting dissociation), but in a non-polar solvent like diethyl ether or tetrahydrofuran (THF), attack by most carbon electrophiles upon indolylmagnesium bromide proceeds at C-3 (Scheme 7.9). 

HMPA hexamethylphosphoric triamide LAH lithium aluminum hydride... 

Compounds (p-YC6H4)2SbBr2(acac) (Y = N02, Cl, H, CI[3, CHsO) were prepared from p-YC6H4SbO(OH)2 11, 18h) and p-YC6H4SbCl3(acac) (Y = N()2, H, CH3) were obtained from corresponding stibonic acid (18a, b). HMPA = hexamethylphosphoric triamide DMSO = dimethyl sulfoxide PyO = pyridine iV-oxide 4-CHjPyO = y-picoline JV-oxide TPPO = triphenylphosphine oxide. 

They may be synthesized by deprotonation and silylation of carboxylic esters or lactones (Equations Si3.15 and Si3.16). Note that in the example depicted in Equation Si3.15 the E isomer is generated if the reaction is performed in THF, but addition of polar HMPA [hexamethylphosphoric triamide, (Mc N P O] to the reaction mixture gives the Z isomer. 

Abbreviations HMPA, hexamethylphosphoric triamide DMSO, dimethyl sulfoxide DMF, dime-thylformamide FA, formamide THF, tetrahydrofuran NM, nitromethane. 

DAST N,A/ -diethylaminosulfur trifluoride HMPA hexamethylphosphoric triamide... 

The synthesis of organolithiums according to Eq. (a) occurs in polar, aprotic solvents, such as tetrahydrofuran (THF), dimethoxyethane (DME) and hexamethyl-phosphoric triamide (HMPA). Hexamethylphosphoric triamide causes tumors and should be handled in a hood with appropriate protective measures. 

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