Lithium 2- pyrrolide

The first pyrrolylphosphazenes were apparently prepared by McBee and coworkers in 1960, and although the work was never documented in the chemical literature, hexakis-(pyrrolyl)cyclotriphosphazene (1) and octakis-(pyrrolyl)cyclotetraphosphazene were described in a Technical Report of the Defense Technical Information Center.19 Compound 1 was reported to be produced in 26% yield from the interaction of hexachlorocyclotriphosphazene [(NPC 2)3] with excess potassium pyrrolide in refluxing benzene over a 24 hour period. Lithium pyrrolide and pyrrolyl magnesium bromide were found to be unsatisfactory reagents for the preparation of 1. 

In the reaction of lithium pyrrolide <1996JOM(514)281> and dialkyl(fluoro)silylamines 253 (R = Pr or Bu ) the dialkyl(l/7-pyrrol-l-yl)silylamines 254 are formed (Scheme 52) <1996JOM(524)203>. 

Another member of this class of substances can be synthesized via the reaction of lithium pyrrolide and N,N-bis[fluoro(diisopropyl)silyl]amine. The monosubstitution product 255 is formed (Equation 61). 

Trichlorosilanes react with lithium indolide under formation of the mono- and bis(177-indol-l-yl)silanes 257 and 258 (Scheme 54) <1996JOM(514)281. In the reaction of lithium pyrrolide snd silsne 257 (R. — Ph) the mono snd bis(17/-pyrrol-l-yl)silanes 259 and 260 are obtained (Equation 62). 

The lithium salt with the 4,5-dicyano-l,2,3-triazolate anion (DCTA-) (also known as 1,2,3-triazole-4,5-dicarbonitrile (TADC-)) (Fig. 1.38p) was first studied by Michot in 1995 [701] and reported in two publications in 2003 [664,665]. Little has been reported regarding the properties of the lithium salt. Alkali and alkali earth salts with the DCTA anion have also been prepared [666,667]. The thermal stability of these salts was found to be excellent (>350 °C) [668]. hi general, triazole salts are known to be energetic. The alkali metal salts, however, were found to have low sensitivity towards impact, friction, electrostatic discharge, and fast heating [668]. The acid with the related pyrazole-3,4,5-tricarbonitrile anion (PATC-) (Fig. 1.38q) was first reported in 1962 [669], but the lithium salt has not been investigated extensively as an electrolyte salt [661, 670,671]. Similarly, the acid with the tetracyano-pyrrolide anion (TCP ) (Fig. 1.38r) was also reported in 1962 [672] and the sodium salt with this anion has been prepared [674]. Trifluoromethane-substituted versions of the C5(CN)5 and TCP" anions have also been reported (Fig. 1.38v, w) [688-692], but the lithium salt has only been reported for LiC5(CF3)5 (Fig. 1.39k) [692]. 

---