DMPU

Bu4N F, DMPU, 4 A molecular sieves, 45-80°, 80-95% yield. These conditions were especially effective in cleaving tertiary SEM derivatives and avoid the use of the toxic HMPA. 

Sml2, DMPU, 50-97% yield. " The reaction works well for alkyl-substituted aziridines benzenesulfonamides react faster than tosyl amides. 

Sml2, THE or DMPU, it, 76-94% yield. Deprotection of the pyridinesul-fonamide in the presence of a cinnamoyl group was possible when done without a proton source. BOC, A-benzyl, A-allyl, and trifluoroacetamido groups were all stable to these conditions. ... 

To a stirred, cold (< —90 C) solution of 10 mmol of the nitroalkanc 1 in 60 mL of TltF/cosolvcnt (IIMPA or DMPU) is added dropwisc a solution of 12.8 mL of 1.16 N BuLi (20.5 mmol) in hexane (in the case of DMPU as cosolvent, the internal temperature is maintained below -88"C). The solution is warmed to... 

The monolithium salt of 4-hydroxy-4-(phenylethynyl)-2.5-cyclohexadienone (12), prepared in situ by the addition of lithium acetylide to /7-benzoquinone, was treated with methylmagnesium chloride in l HF-TMEDA or in THF —DMPU. The syn-, 4-addition adduct 13, derived from intramolecular delivery of the carbon nucleophile by the hydroxy oxygen, as well as the <7s-1,4-diol 14, obtained via intermolecular 1,2-addition, were obtained in varying amounts depending on the conditions. The selectivity on 1,4- to 1,2-addition increased by the addition of cation chelating agents such as DMPU, TMEDA, and 15-crown-5. Although the 1,4 to 1,2... 

The effect of chelating polyamines on the rate and yield of benzylation of the lithium enolate of 1-tetralone was compared with HMPA and DMPU. The triamine... 

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