55124-36-2Relevant academic research and scientific papers
Direct preparation and structure determination of tertiary and secondary amine boranes from primary or secondary amine boranes
Shibli, Amal,Ali, Hijazi Abu,Goldberg, Israel,Srebnik, Morris
, p. 2180 - 2185 (2007/10/03)
New secondary and tertiary amine borane derivatives were prepared in a one-pot reaction starting from primary amine boranes. The reaction involves treatment of an amine borane with 2 equivalents of s-BuLi at -78 °C. In general, mixtures of mono and di metallated products were obtained. Alkyl iodides and benzyl chloride reacted with the lithiated amine, but aldehydes and ketones were reduced. Conversion was high as determined by NMR, but moderate to low yields were obtained after chromatography, possibly due to decomposition on silica. Crystal structures were obtained for the compounds 3a, 3b and 3c.
Studies of 2,5;6,10;8,10-Tri-μ-hydro-nonahydro-nido-nonaborate(1-), -: Preparation, Crystal and Molecular Stucture, Nuclear Magnetic Resonance Spectra, Electrochemistry, and Reactions
Jacobsen, Grant B.,Meina, Dominic G.,Morris, John H.,Thomson, Colin,Andrews, Steven J.,et al.
, p. 1645 - 1654 (2007/10/02)
Studies of 2,5;6,10;8,10-tri-μ-hydro-nonahydro-nido-nonaborate(1-) - have involved new syntheses, which have led to crystals suitable for the determination of the X-ray crystal and molecular structure, through reactions of B9H13(SMe2) with - or other bases.Crystallographic study of reveals the structure of the anion to be that of a nido-nine-vertex cage, based on the parent bicapped square antiprism with one 5-connected vertex removed.The pentagonal open face is symmetrically bridged by three (μ-H) atoms (two involving the lowest connected boron), conferring effective Cs symmetry upon the polyhedron.Crystals are monoclinic, space group P21/n, with a=26.759(10), b=10.340(4), c=27.044(5) Angtroem, β=103.47(2) deg, and Z=8.Using 6 777 diffracted intensities recorded at 185 K on an Enraf-Nonius CAD4 diffractometer, the structure has been refined to R 0.0847, R' 0.1216.The 11B, two-dimensional 11B(COSY), and 1H n.m.r. parameters all confirm the structural assignment and the n.m.r. spectra have been assigned unambiguously.Cyclic and a.c. voltammetry and coulometry of - in several solvents at Pt led to the electrochemical parameters and to an isomer-specific electrochemical synthesis of anti--.Chemically, the + salt of - reacted with HCl to give -, whereas the n4>+ salt yielded anti-B18H22; reactions with CF3CO2H gave primarily anti--.
Dialkylaminohydridophenoxyboranes. Convenient preparation and studies of intramolecular boron-nitrogen π bonding
Kovar, Roger A.,Waldvogle, Gene G.
, p. 2239 - 2243 (2008/10/08)
A convenient preparation of dialkylaminohydridophenoxyborane compounds (HBOC6H5NR'2) has been developed according to the following three-step sequence: (1) 4BF3 (etherate) + 3NaBH4 = 3NaBF4 + 2B2H6(g); (2) 1/2B2H6(g) + HNR'2 = H3BNHR'2; (3) H3BHNR'2 + HOC6H5 + heat = 2H2 + HBOC6H5NR'2; HNR'2 = HN(CH3)2, HN(C2H5)2, HN(i-C3H7)2, HN(n-C4H9)2, HN(CH2C6H5)2, HNC4H8, and HNC5H10. The final products are isolated in yields ranging from 70 to 90% by vacuum distillation at moderate temperatures. Molecular association and variable-temperature proton magnetic resonance studies of these compounds in benzene solution are consistent with a planar, monomeric configuration with considerable π interaction between boron and nitrogen and hindered rotation about this bond. The Lewis acid behavior of diisopropylaminohydridophenoxyborane toward ammonia and trimethylamine was determined using a tensimetric titration procedure. No evidence of interaction was observed with trimethylamine while a stable 1:1 adduct was formed in the case of the reaction involving ammonia: HBOC6H5N(i-C3H7)2 + NH3 = HBOC6H5N(i-C3H7)2-NH 3. The room-temperature proton magnetic resonance spectrum of the ammonia adduct of diisopropylaminohydridophenoxyborane has demonstrated relatively unrestricted rotation about the secondary amino nitrogen-boron bond.
