Lynn Mandy, Pierson Smela Merrick, Hoye Thomas R
Department of Chemistry, University of Minnesota 207 Pleasant St. SE Minneapolis MN 55455 USA
Chem Sci. 2021 Oct 6;12(41):13902-13908. doi: 10.1039/d1sc04082k. eCollection 2021 Oct 27.
The 1,3-diyne and diynophile in hexadehydro-Diels-Alder (HDDA) reaction substrates are typically tethered by linker units that consist of C, O, N, and/or S atoms. We describe here a new class of polyynes based on silicon-containing tethers that can be disposed of and/or functionalized subsequent to the HDDA reaction. The cyclizations are efficient, and the resulting benzoxasiloles are amenable to protodesilylation, halogenation, oxygenation, and arylation reactions. The presence of the silicon atom can also override the innate mode of cyclization in some cases, an outcome attributable to a β-silyl effect on the structure of intermediate diradicals. Overall, this strategy equates formally to an otherwise unknown, bimolecular HDDA reaction and expands the versatility of this body of aryne chemistry.
在六脱氢狄尔斯-阿尔德（HDDA）反应底物中，1,3-二炔和亲双烯体通常由包含碳、氧、氮和/或硫原子的连接单元连接。我们在此描述了一类基于含硅连接基的新型聚炔，其在HDDA反应后可进行去除和/或功能化。环化反应高效，所得苯并硅杂环戊二烯适合进行原硅烷基化、卤化、氧化和芳基化反应。在某些情况下，硅原子的存在还可改变固有的环化模式，这一结果归因于β-硅基对中间双自由基结构的影响。总体而言，该策略形式上等同于一种未知的双分子HDDA反应，并扩展了这类芳炔化学的应用范围。
