Lithium trialkylborohydride

Litkiam trialkylborohydrides. The reaction of r-butyllithium with trialkyl-boranes provides a convenient route to lithium trialkylborohydrides.- ... 

Selective reductions. As expected, this dialkylborohydride shows reducing properties intermediate between those of the mild lithium borohydride and of the powerful lithium trialkylborohydrides. As a result, it is particularly useful for selective reductions. 

Lithium naphthalenide, 284-285 Lithium phenylthio(trimethylstannyl)-cuprate, 330 Lithium phthalide, 285 Lithium 2,2,6,6-tetramethylpiperidide, 145, 281,285-286, 362 Lithium trialkylborohydrides, 278 Lithium triethylborohydride, 286 Lithium tricthylborohydride-Aluminum t-butoxide, 287 Lycorine, 503... 

Borohydride Reagent. Treatment of NB-enantrane with t-Butyllithium provides the lithium trialkylborohydride NB-Enantride (eq 4). This reagent is an effective asymmetric reducing agent for acetophenone and alkyl methyl ketones such as 2-octanone (eq 5). Few reagents show selectivity for such alkyl ketones. 

The atmospheric pressure carbonylation of undissociated alkali-metal tri-alkylborohydrides is unsuccessful, but rapid reaction has been found to occur if catalytic amounts of free trialkylborane are present (as is the case for lithium trialkylborohydrides), or are added to the mixture (Scheme 4). Hydrolysis of the... 

Two new procedures for the in situ generation of lithium trialkylborohydrides have been disclosed. In the first, trialkylboranes are allowed to react with lithium trimethoxyaluminium hydride [equation (1)], and the resultant solution... 

The reaction between several dialkylboranes and organolithium reagents (MeLi, BuLi, PhLi) produced not the lithium trialkylborohydride LiR R BH, but equal amounts of the mixed lithium tetra-alkylborate, LiR 2R aB, and the lithium dialkylborohydride, LiR gBH 2. ... 

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