Synthesis of Substituted Oxa- and Aza[3.2.1] and [4.3.1]Bicyclics via an Unprecedented Molybdenum-Mediated 1,5-“Michael-Type” Reaction

The direct internal nucleophilic functionalization of a π-bound carbon of neutral TpMo(CO)2(5-oxo-η3-pyranyl) and TpMo(CO)2(5-oxo-η3-pyridinyl) complexes by enolates represents a new reaction profile for neutral TpMo(CO)2(η3-allyl) complexes. This Mo-mediated “1,5-Michael reaction” proceeds in good to excellent yields and provides, after demetalation, a new and efficient synthetic approach to oxa- and aza[3.2.1]bicyclics of high enantiomeric purity.

烯醇负离子对中性TpMo(CO)₂(5-氧代-η³-吡喃基)与TpMo(CO)₂(5-氧代-η³-吡啶基)配合物中π键合碳原子的直接分子内亲核官能化，为中性TpMo(CO)₂(η³-烯丙基)配合物开辟了全新的反应模式。该钼介导的“1,5-迈克尔反应”可获得良好至优异的反应收率，经脱金属化后，可得到高对映体纯度的氧杂与氮杂[3.2.1]双环类化合物，为这类化合物的合成提供了新颖高效的途径。