ISSN:
0009-2940
Keywords:
1,2-Azaboroles, phosphanyl-substituted, X-ray structure analysis
;
Thallium-, 1,2-azaborolyl-
;
Stereoselectivity
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
1,2-Azaborolyl Complexes, XXX[1]. - Phosphanyl-Substituted 1,2-Azaboroles1-tert-Butyl-2-methyl-1,2-azaborolyllithium (LiAb, 1) and TlCl equilibrate at -75°C in THF under action of light to TlAb (2) and LiCl. Compound 2 decomposes above -50°C with elimination of thallium and the neutral isomers 1-tert-butyl-2,5-dihydro-2-methyl-1H-1,2-azaborole and 1-tert-bu-tyl-2,3-dihydro-2-methyl-1H-1,2-azaborole. Whilst 1 reacts with Ph2PCl in only very small amounts to give the expected Ph2P-substituted azaborole ring 3, TlAb (2) forms this compound by reaction with Ph2PCl in high yields. The yellow oily 3 is characterized by 1H-; 11B-, 13C-, and 31P-NMR data. The Me3Si-substituted derivative 1-tert-butyl-3-(diphenyl-phosphanyl)-2,3-dihydro-2-methyl-3-(trimethylsilyl)-1H-1,2-azaborole (5), available via 4, the Li salt of 3, and ClSiMe3, forms yellow crystals which could be used for an X-ray structure analysis. As expected, the Ph2P and Me3Si groups substitute the boron neighboring C3 atom of the planar ring framework. The crystal structure of 5 shows the two expected enantiomers.
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19941271012
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