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

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Other information

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

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Abstract

V originále

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.