The Scope and Limitations of 1,3-Stannyl Shift-Promoted Intramolecular Cyclizations of α-Stannyl Radicals with a Formyl Group
作者:Shau-Hua Ueng、Ming-Jen Chen、Shu-Fang Chu、Yar-Fang Shao、Gang-Ting Fan、Sheng-Yueh Chang、Yeun-Min Tsai
DOI:10.1021/jo052176v
日期:2006.2.1
and serves as a driving force to promote the cyclizations. Although the cyclization rates can be accelerated when the formyl group carries α-dimethyl substituents, unfortunately β-scission of the alkoxy radicals becomes competitive with the 1,3-stannyl shift. The β-stannyloxy radicals can be employed in further cyclizations to obtain tandem cyclization products.
α-三丁基锡烷基可以由相应的溴化物或黄药生成。这些基团经过带有甲酰基的有效分子内1,5-环化反应。所得的β-锡烷基烷氧基通过从碳到氧的1,3-锡烷基转移进行,以提供β-锡烷基氧基。这种新颖的重排极有可能是不可逆的,并且是促进环化的驱动力。尽管当甲酰基带有α-二甲基取代基时可以加快环化速率,但是不幸的是,烷氧基的β-断裂与1,3-锡烷基移位竞争。可以将β-锡烷基氧基用于进一步的环化以获得串联环化产物。