Synthesis and derivatization of naphthylcalcium halides as well as degradation in THF solution

Abstract The direct synthesis of 1-naphthyliodide and -bromide with calcium powder yields (thf) 4 Ca(Naph)I ( 1 ) and [(thf) 3 Ca(Naph)Br] 2 ( 2 ), respectively. The metathesis reaction of 1 with KN(SiMe 3 ) 2 gives (thf) 3 Ca(Naph)–N(SiMe 3 ) 2 ( 3 ). In 2 and 3 very small Ca–C bond lengths of 252.8(4) and 251.4(6) pm, respectively, are observed. These compounds slowly decompose in THF solution via ether cleavage reactions. From this degradation, [(thf) 4 CaBr 2 ] · naphthalene ( 4 ) crystallizes from THF solutions. Furthermore, decomposition of 1 in THF solution yields ethene and naphthalene whereas intermediate ethenolate undergoes subsequent degradation to an acetylide.