Preparation of novel selenapenams and selenacephems by nucleophilic and radical chemistry involving benzyl selenides
作者:Michael W. Carland、Robyn L. Martin、Carl H. Schiesser
DOI:10.1039/b409242b
日期:——
2,2a-Dihydro-1H,8H-azeto[2,1-b][1,3]benzoselenazin-1-one (12), 5-selena-1-azabicyclo[4.2.0]oct-3-en-8-one (13), ethyl 1-aza-7-oxo-4-selenabicyclo[3.2.0]heptane-2-carboxylate (16), and benzoselenopenem (33) can be prepared in 39–85% yield through the intramolecular homolytic substitution of aryl, vinyl or alkyl radicals at the selenium atom in suitably-substituted 4-benzylseleno-β-lactams, or through intramolecular nucleophilic substitution by the benzylseleno moiety in 4-halo-β-lactam precursors. Application of this chemistry to the preparation of optically active selenium-containing analogues of β-lactam antibiotics is also detailed.
2,2a-二氢-1H,8H-氮杂[2,1-b][1,3]苯硒嗪-1-酮(12)、5-硒-1-氮杂双环[4.2.0]辛-3-烯-8-酮(13)、乙基1-氮杂-7-氧-4-硒双环[3.2.0]庚-2-羧酸酯(16)和苯并硒烯酮(33)可以通过适宜取代的4-苯基硒-β-内酰胺中的硒原子上对芳基、烯基或烷基自由基的分子内均裂替换,或者通过4-卤代-β-内酰胺前体中苄基硒基团的分子内亲核替换,得到39~85%的产率。此外,文中还详细描述了这种化学方法在制备光学活性含硒β-内酰胺抗生素类似物方面的应用。