Oligomers with Four-Coordinate Annular Boron and Nitrogen

6 Oligomers with Four-Coordinate Annular Boron and Nitrogen 

5 Boron-Nitrogen Heterocycles Containing AdditionalHeteroatomsOtherThan Carbon 

Syntheses have been developed for boroxazines of types 64 and 65. The bicyclic compound 66 is obtained only as a by-product [26]. 

Three-membered azasilaboracyclopropanes 67 are formed by treatment of diaminobor-anes of the general formula (/-C3H7)2N-B(Cl)-N(C4H9-f)-Si(CH3)(R)Cl, where R = CH3 or C2H5, with sodium/potassium alloy in hexane they have been characterized by NMR data ( H, B with 6 B = 27.9 for 67a and 24.0 ppm for 67b C) [3]. 

The unique species 69 is formed by thermolysis of Cl2BN(SiCl3)2 in 50% yield. The boiling point is 140°C/0.01 Torr, the melting point 124 to 126°C. The IR spectrum has been recorded and assigned [27]. 

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