Tetra-alkylborates

Hydroxy-a-diazoketones, generated by addition of the lithium derivatives of a-diazoketones to an aldehyde, give ynones on treatment with boron trifluoride.The addition of copper tetra-alkylborates to ynones occurs in a stereocontrolled cis manner to afford the corresponding enones [equation (29)]. ""... 

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. ... 

Anionic complexes. The type M BR4 has already been mentioned in connection with tetraphenylborates (p 77). Tetra-alkylborates are also known, and can be prepared from e.g. R3B+RL1, conveniently in benzene ... 

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See also in sourсe #XX -- [ ]

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