ISSN:
1434-1948
Keywords:
B,B′-Dimesityldiborane(4) dihalides
;
B,B′-Diamino-B,B′-dimesityldiboranes(4)
;
B,B′-Di-tert-butyloxy-B,B′-dimesityldiborane(4)
;
B,B′-Dimesityl-B,B′-di(organylthio)diborane(4)
;
NMR spectroscopy
;
X-ray structures
;
Chemistry
;
General Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
An efficient route to B,B′-dihalo-B,B′-dimesityldiboranes(4) is reported, as well as the conversion of these and of B,B′-dimesityl-B,B′-dimethoxydiborane(4) into other B,B′-dimesityldiboranes B2mes2X2 (X = OR, SR, NR2, NHR). The substituents X influence the shielding of the 11B nucleus in the expected manner. Hindered rotation about the B-N bond is observed for X = pyrrolyl, while in solution there is free rotation about the B-C bond. However, X-ray structural results reveal that the mesityl group is almost orthogonal to the B(B)CY plane in the solid state. The shortest B-B bond is observed in mes2B2I2, indicating that the iodide is the strongest Lewis acid in the reported series of mes2B2Y2 compounds. This is also reflected in short B-C bonds. Moreover, the two mes(Y)B units also approach orthogonality in these diborane(4) compounds, and thus enforce this as a typical structural feature of diborane(4) derivatives. For this reason, the planar C(N)B-B(N)C unit of B,B′-di(benzylamino)-B,B′-dimesityldiborane(4) is regarded as exceptional for aminodiboranes(4).
Type of Medium:
Electronic Resource
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