20692-59-5Relevant articles and documents
Structural studies of organoboron compounds. XXVIII. 5,5-Trimethylene-2,2-diphenyl-1,3-dioxa-5-azonia-2-boratacyclohexane and 5,5-dimethyl-2,2-diphenyl-1,3-dioxa-5-azonia-2-boratacyclohexane monohydrate
Kliegel,Wolfgang,Rettig, Steven J.,Trotter, James
, p. 377 - 384 (2007/10/02)
The preparation of the title compounds demonstrates the bis-N-alkylation of secondary amines by formaldehyde, these labile ammonium inner salts being captured as diphenylboron chelates.Crystals of 5,5-trimethylene-2,2-diphenyl-1,3-dioxa-5-azonia-2-boratacyclohexane are orthorhombic, a = 8.8461(3), b = 10.7290(4), c = 15.8773(5) Angstroem, Z = 4, space group P212121, and those of 5,5-dimethyl-2,2-diphenyl-1,3-dioxa-5-azonia-2-boratacyclohexane monohydrate are monoclinic, a = 6.2432(3), b = 17.1469(8), c = 14.3701(5) Angstroem, β = 90.647(3) deg, Z = 4, space group P21/n.Both structures were solved by direct methods and were refined by full-matrix least-squares procedures to R = 0.030 and 0.047 for 1400 and 2258 reflections with I >= 3?(I), respectively.Both compounds have a B,N-betaine structure, the six-membered chelate rings adopting chair conformations.Libration-corrected bond lengths, O-B = 1.508(3)-1.522(3) and C-B = 1.612(4)-1.637(4) Angstroem, indicate relatively strong binding of the diphenylboron moiety to the oxygen atoms of the O,O-chelating ligands.
