34574-27-1Relevant academic research and scientific papers
Pyrazole complexes of acyloxydialkylboranes
Dabrowski, Marek,Klis, Tomasz,Lulinski, Sergiusz,Madura, Izabela,Serwatowski, Janusz,Zachara, Janusz
, p. 31 - 37 (1998)
The reaction of Me3CCOOBEt2 with pyrazole led to the formation of the stable addition complex 1, which was found to be monomeric in solution. The reaction of 9-H-9-borabicyclo[3.3.1]nonane (9-H-9-BBN)2 with pyrazole and pivalic acid yielded a similar complex Me3CCOO(9-BBN)-pzH 2. Crystallographic analysis of 2 revealed a dimeric structure due to the strong hydrogen bonding between azole hydrogen and carbonyl oxygen. The one boron-carbon bond of compound 1 cleaves readily with triethylborane at 20°C with the evolution of ethane, giving a species Me3CCOO(BEt2)2pz 3 with a seven-membered heterocyclic ring as the main structural feature.
Monomeric and Dimeric Acyloxydialkylboranes
Yalpani, Mohamed,Boese, Roland,Seevogel, Klaus,Koester, Roland
, p. 47 - 50 (2007/10/02)
The carboxylic acids RCO2H t a, Et b, 3,4,5-(MeO)3C6H2 c, 4-MeOC6H4 d, Ph e, 2,4,6-Me3C6H2 f, 2,6-Cl2C6H3 g, or 3,5-(CF3)2C6H3 h> were treated with triethylborane or with bis(9-borabicyclononane) to give the acyloxydiethylboranes 1a-1h and the 9-acyloxy-9-(borabicyclononanes) 2a-2h, respectively.Compounds 1a-1h are largely unassociated in nonpolar solvents ((11)B NMR, IR spectroscopy).As pure liquids, or in the solid state, they form equilibrium mixtures of monomeric and associated (dimeric) molecules (IR spectroscopy).Compounds 2a-2f are completely associated as pure liquids and in the solid state, but only weakly associated in non-polar solvents.Based in the crystal structure of dimeric 2e, it is proposed that, when associated, derivatives of both 1 and 2 form cyclic dimers.
