W. Kliegel, G. Lubkowitz, S. Rettig
Dec 1, 1993
Citations
0
Influential Citations
6
Citations
Journal
Canadian Journal of Chemistry
Abstract
The syntheses of the sterically hindered N,N′-dihydroxyaminals; N,N′-bis(1-ethoxycarbonyl-1-methylethyl)-N,N′-dihydroxymethanediamine, 1b, and N,N′-bis(1,1-dimethylethyl)-N,N′-dihydroxymethanediamine, 1c, and their reactions with phenylboronic acid to yield the 1,3,5-trioxa-6,8-diaza-2,4-diboracyclooctanes 3 and 4, respectively, are described. Crystals of 1b are tetragonal, a = 18.413(1), c = 9.867(2) A, Z = 8, space group I41; those of 3 are monoclinic, a = 20.420(4), b = 8.272(4), c = 17.851(5) A, β = 117.34(1)°, Z = 4, space group C2/c; and those of 4 are monoclinic, a = 9.493(4), b = 16.202(4), c = 14.783(3) A, β = 101.90(2)°, Z = 4, space group P21/c. The structures were solved by direct methods and were refined by full-matrix least-squares procedures to R = 0.034, 0.039, and 0.040 (Rw = 0.035, 0.034, and 0.036) for 1550, 1438, and 2187 reflections with I ≥ 3σ(F2), respectively. In the solid state, both 3 and 4 exhibit transannular interactions. In 3 there are two identical (by symmetry) interactions...