Alkalimetall‐trialkylhydroxyborate und (Alkalimetalloxy)dialkylborane [1]
1992; Wiley; Volume: 125; Issue: 3 Linguagem: Inglês
10.1002/cber.19921250313
ISSN0009-2940
AutoresRoland Köster, Günter Seidel, Bernd Wrackmeyer,
Tópico(s)Chemical Synthesis and Characterization
ResumoAlkalimetal Trialkylhydroxyborates and (Alkalimetaloxy)dialkylboranes [1] Et 3 B ( 1 ) and 9‐Et‐9‐BBN ( 2 ) react with alkalimetal hydroxides (LiOH, NaOH, KOH) to yield the alkalimetal hydroxytriorganoborates M‐ 3 and M‐ 4 , resp. Heating (about 100°C) of the borates, catalyzed by NaHBEt 3 , leads to elimination of ethane with formation of the boranes MOBEt 2 (M‐ 5 , M = Na, K) or MOBC 8 H 14 (M‐ 7 , M = Li, Na, K), which associate to compounds with BOB, BOM, or MOM bridge bonds. At temperatures higher than 160°C (without catalyst), M‐ 3 (M = Li, Na) and Li‐ 4 dissociate. Na‐ 4 is dehydroborated with formation of H 2 and NaOB(Et)C 8 H 13 (Na‐ 9 ). From K‐ 7 and ClSiMe 3 9‐Me 3 SiO‐9‐BBN ( 10 ) is obtained. Na‐ 9 reacts with ClSiMe 3 to give a mixture of the unsaturated mixed borane 11 and the mixed diboroxane 12 . The degree of the association of the alkalimetal compounds were determined by the specific electric conductivity measurements ( K ) and by 17 O‐NMR spectroscopy.
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