Organometallic Enantiomeric Scaffolding: General Access to 2-Substituted Oxa- and Azabicyclo[3.2.1]octenes <i>via</i> a Brønsted Acid Catalyzed [5 + 2] Cycloaddition Reaction
作者:Ethel C. Garnier、Lanny S. Liebeskind
DOI:10.1021/ja800664v
日期:2008.6.1
6-Substituted TpMo(CO) 2(eta-2,3,4-pyranyl)- and TpMo(CO) 2(eta-2,3,4-pyridinyl) scaffolds (Tp = hydridotrispyrazolylborato) function as reaction partners in an efficient regio- and stereocontrolled synthesis of functionalized oxa- and azabicyclo[3.2.1]octenes through a novel Brønsted acid catalyzed [5 + 2] cycloaddition reaction. Excellent exo-selectivities are obtained, and the reaction gives products with
6-取代的 TpMo(CO) 2(eta-2,3,4-pyranyl)- 和 TpMo(CO) 2(eta-2,3,4-pyridinyl) 支架(Tp = 氢化三吡唑基硼酸)作为反应伙伴以高效的方式发挥作用通过新型布朗斯台德酸催化的 [5 + 2] 环加成反应,功能化氧杂和氮杂双环 [3.2.1] 辛烯的区域和立体控制合成。获得了优异的外选择性,当使用手性非外消旋支架进行反应时,该反应产生的产物完全保留了对映体纯度。η (3) 配位杂环支架的 C-6 处的取代基不仅影响 [5 + 2] 反应性,而且在脱金属步骤中起着关键作用,将反应引导至两种可能的产物中的一种。