Zr-promoted ‘pair’-selective and regioselective synthesis of penta-substituted benzene derivatives
摘要:
Tetra-substituted zirconacyclopentadiene derivatives, obtainable via in situ generation of zirconacyclopropenes and their cyclic carbozirconation with alkynes, can be treated with alkynyllithiums to induce 1,2-migration accompanied by aromatization and protonolysis, leading to the formation of penta-substituted benzene derivatives, in which all five substituted may be different. (C) 2003 Elsevier Ltd. All rights reserved.