Lithium diethylamide-Hexamethylphosphoric triamide

DIKETONES 3-Benzyl-5-(2-hydroxyethyl)-4-methyl-l, 3-thiazolium chloride. Bis(methylthio)(trimethylsilyl)methyllithium. Cupric chloride. Di(a-methoxy-vinyl)copperlithium. Lithium diethylamide-Hexamethylphosphoric triamide. 

For use of dimethylhydrazones in a conversion of aldehydes into nitriles see Lithium diethylamide-Hexamethylphosphoric triamide (this volume). 

CYCLOPROPANF.S Benzyltriethylammonium chloride. Dicobalt octacarbonyl. Lithium diethylamide-Hexamethylphosphoric triamide. Lithium diisoptopylamido-Hexa-methylphosphoric triamide. 

NITRILES Acrylonitrile. N-Amino-4,6-diphenylpyridone. n-Hexylamine. Hydroxyl-amine hydrochloride. lithium diethylamide-Hexamethylphosphoric triamide. Methyl carbazate. Phenyl isocyanate. p-Toluenesulfonic acid. Trifluoromethanesulfonic an-... 

Formation of the enolate from 1-methyl-2-pyrrolidone (a y-lactam) is accomplished by treatment with lithium diethylamide in hexamethylphosphoric triamide/benzene at — 20 °C. Addition of bromomethane or (chloromethyl)benzene then results in good yield of the a-alkylation product15. 

Thus, starting from the (—)-(S )-a-(methoxymethyl)benzeneethanaminc derived imines at low temperatures, (S )-2-methylcycloalkanones are obtained via the -azaenolates, whereas (R)-configurated products are obtained via the thermodynamically more stable Z-azaenolates by refluxing the anion solutions prior to alkylation. However, a high degree of enantiomeric excess is obtained only under thermodynamic conditions, presumably due to different selectives in the alkylation step (see Table 3). Variation of the base (/ert-butyllithium, lithium diethylamide, lithium 2,2,6,6-tetramethylpiperidide) and additives (hexamethylphosphoric triamide) did not improve the EjZ ratio (enantiomeric excess) significantly9. 

BASF AG CRBPII dba DBN DBU DIBAL-H DMAP DMF DMF-DMA DMPU HMDS HMPA HMPT H-LR LDA LDE LRAT MCPBA MOM NMO NMP PCC PhH = Badische Anilin- Soda Fabrik AG = cellular retinol-binding protein type II r dibenzylideneacetone = 1,5-diazabicyclo[4.3.0]non-5-ene = l,8-diazabicyclo[5.4.0]undec-7-ene = diisobutylaluminium hydride = 4-dimethylaminopyridine = A V-dimethylformamide = A,V-dimethylformamide, dimethylacetal = 1,3 -dimethyl-3,4,5,6-tetrahydro-2( 1H)-pyrimidone = hexamethyldisilazane = hexamethylphosphoramide = hexamethylphosphorous triamide = Hoffmann-La Roche = lithium diisopropylamide = lithium diethylamide = lecithin retinol acyltransferase = m-chloroperbenzoic acid = methoxymethyl = iV-methylmorpholine oxide = l-methyl-2-pyrrolidinone = pyridinium chlorochromate = benzene... 

However, isomerization by lithium diethylamide in hexamethylphosphoric triamide at 35°C, within 15 minutes gave enJo-bicyclo[5.1.0]oct-5-en-ol (1). ... 

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