Structural studies of organoboron compounds XL. 4,7-Dicyclohexyl-2,2,5,6-tetraphenyl- 1,3-dioxa-4-aza-7-azonia-2-boratacycloheptane

Abstract

. 68, 1797 (1990). The synthesis of 4,7-dicyclohexyl-2,2,5,6-tetraphenyl-l,3-dioxa-4-aza-7-azonia-2-boratacycloheptane is reported. Crystals of the compound are orthorhombic, a = l0.893(1), b = 28.072(1), c = 10.596(1) A, Z = 4, space group P212121. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to R = 0.036 and R,,. = 0.043 for 2480 reflections with1 2 3u(I). The molecule has a seven-membered chelate structure. The seven-membered ring, which has a twisted chair conformation, is stabilized b an intramolecular N-H...O hydrogen bond. Bond lengths &B = 1.468(4) and 1.554(4), C-B = 1.621 (5) A sont en accord avec une liaison relativement forte de la portion diphtnylbore par le ligand 0,O-chtlatant.Mots clis : structure cristalline, compost du organobore, compost du bore.[Traduit par la revue]

Structural studies of organoboron compounds. LII. N-Ethylhydroxylamine- (O-B)1,7-diethyl-3,5-diphenyl-2,4,6-trioxa-7-aza-1-azonia-3-bora-5- boratabicyclo[3.3.0]octane

“…Compound 2 would be analogous to the sevenmembered ring derivative 3 which had been obtained by a similar method from an N,N1-dihydroxy-l,2-ethanediamine and diphenylborinic acid. The structure of 3 has been established by X-ray analysis (1). Contrary to expectations, the crystalline material obtained from the reaction of 1 and oxybis(dipheny1borane) did not give the typical blue color reaction with diphenylcarbazone (2) which would indicate the presence of an intact diphenylboron moiety (by trapping of Ph,B+).…”

Structural studies of organoboron compounds. LV. N,N′-Di-tert-butyl-N,N′- dihydroxypropane-1,3-diamine(O-B)ethoxydiphenylborane and N1,N2-di-tert-butyl-N1,N2-dihydroxy-1-phenylpropane-1,3-diamine(N2-O-B)hydroxydiphenylborane

“…The 1,3-bishydroxylamines 2 (R = H or C,H,) were then reacted with oxybis(dipheny1borane) in ethanolic solution in order to prepare the eight-membered diphenylboron chelates 3 . These compounds would be analogous to the seven-membered chelate 4 that is obtained under the same conditions from a 1,2-bis-hydroxylamine (2). The crystalline reaction products derived from 2u and 26 show the elemental analyses and 'H nrnr spectra of the expected derivatives plus 1 molar equivalent of ethanol in the case of 3a, and 1 molar equivalent of water in the case of 36.…”