Group 13 Azatranes: Synthetic, Conformational, and Configurational Features.

PINKAS, Jiří, B. GAUL and J. G. VERKADE. Group 13 Azatranes: Synthetic, Conformational, and Configurational Features. Journal of the American Chemical Society. Washington, D.C.: American Chemical Society, 1993, vol. 115, No 10, p. 3925-3931. ISSN 0002-7863.

Basic information

• Original name: Group 13 Azatranes: Synthetic, Conformational, and Configurational Features.
• Authors: PINKAS, Jiří, B. GAUL and J. G. VERKADE.
• Edition: Journal of the American Chemical Society, Washington, D.C. American Chemical Society, 1993, 0002-7863.

Other information

• Original language: English
• Type of outcome: Article in a journal
• Field of Study: 10402 Inorganic and nuclear chemistry
• Country of publisher: United States of America
• Confidentiality degree: is not subject to a state or trade secret
• Organization unit: Faculty of Science
• Keywords in English: AZASILATRANES; NITROGEN
• Tags: AZASILATRANES, Nitrogen

Abstract

The monomeric azatranes E(RNCH2CH2)3N 7 (E = B, R = Me), 8 (E = B, R = SiMe3), and 9 (E = Al, R = SiMe3) can be synthesized from E(NMe2)3 and (HRNCH2CH2)3N in low yields (6-37%). The azatrane 10 (E = Al, R = Me), formed in 64% yield by the analogous reaction, is a stable dimer featuring a four-membered MeNAlNMeAl ring in which the aluminum is five-coordinate as shown by H-1, C-13, and Al-27 NMR spectroscopic techniques (including two-dimensional ones). Compound 7 can be made in 30% yield by reacting 10 with B(OMe)3. Compound 8, in contrast to 7 and 9, exists as rigid enantiomers that interconvert slowly at room temperature on the NMR time scale owing to steric repulsion of the Me3Si groups. VT H-1 and B-11 NMR studies provide evidence for a concerted (rather than a stepwise) racemization mechanism (DELTAH(double dagger), 61 +/- 5 kJ.mol-1; DELTAS(double dagger), -36 +/- 13 J.mol-1 K-1) involving a symmetric (C3v) transition state that retains the transannular bond.