Royzen Maksim, Yap Glenn P A, Fox Joseph M
Brown Laboratories, Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, USA.
J Am Chem Soc. 2008 Mar 26;130(12):3760-1. doi: 10.1021/ja8001919. Epub 2008 Mar 6.
Described is a scalable procedure for driving photochemical sytheses of trans-cyclooctene derivatives through metal complexation. During photoirradiation, reaction mixtures are continuously pumped through a column of a AgNO3-impregnated silica gel. The trans-cyclooctene derivative is selectively retained by the AgNO3-impregnated silica, but the cis-isomer elutes from the column back to the reaction flask, where it is photoisomerized and recirculated through the column. The method provides access to a range of usefully functionalized derivatives of trans-cyclooctene, including a derivative of 5-aza-trans-cyclooctene that underwent transannular cyclization upon treatment with bromine. The alkene stereochemistry is transferred with high fidelity to the hexahydropyrrolizine framework in the transannular cyclization.
描述了一种通过金属络合驱动反式环辛烯衍生物光化学合成的可扩展方法。在光辐照期间，反应混合物连续泵送通过填充有硝酸银浸渍硅胶的柱。反式环辛烯衍生物被硝酸银浸渍的硅胶选择性保留，但顺式异构体从柱中洗脱回到反应烧瓶，在那里它被光异构化并通过柱再循环。该方法提供了一系列有用的反式环辛烯官能化衍生物，包括一种5-氮杂反式环辛烯衍生物，该衍生物在用溴处理时发生跨环环化。在跨环环化中，烯烃立体化学以高保真度转移到六氢吡咯嗪骨架上。
