Synthesis and characterization of the first examples of 1,3,2-diazastibole and 1,3,2-diazabismole ring compounds

✍ Scribed by Bruce N. Diel; Timothy L. Huber; William G. Ambacher

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 229 KB
• Volume: 10
• Category: Article
• ISSN: 1042-7163
• DOI: 10.1002/(sici)1098-1071(1999)10:5<423::aid-hc13>3.0.co;2-b

✦ Synopsis

Reaction of either 9,

or diphenylethanedione (benzil) with two equivalents of Li[N(SiMe 3 ) 2 ], followed by quenching of the reaction with excess Cl-SiMe 3 , produces the corresponding N,NЈbis(trimethylsilyl)-␣-diimines in high yields (85-95%). Subsequent dehalosilylation/ring-closure reactions with SbCl 3 and BiCl 3 produce, in 90-95% yields, the first examples of 1,3,2-diazaheterole ring compounds containing antimony or bismuth. These 2-chloro-1,3,2-diazaheteroles can be further functionalized at the pnictogen by reaction with, for example, Li[N(SiMe 3 ) 2 ], to produce the corresponding 2bis(trimethylsilyl)amido-1,3,2-diazaheteroles. All of these new main group element-containing heterocycles have been characterized through 1 H and 13 C NMR, elemental analysis, and two of the diazastiboles have been structurally characterized by single-crystal X-ray analysis, confirming the ring structures. Both of these diazastiboles exist as associated dimers in the solid state; half of the dimer represents the asymmetric unit.