Department of Chemistry and Biochemistry, San Diego State University, San Diego, California 92182, United States.
J Org Chem. 2020 Nov 6;85(21):13895-13905. doi: 10.1021/acs.joc.0c01917. Epub 2020 Oct 12.
We report a highly efficient ortho-selective electrophilic chlorination of phenols utilizing a Lewis basic selenoether catalyst. The selenoether catalyst resulted in comparable selectivities to our previously reported bis-thiourea ortho-selective catalyst, with a catalyst loading as low as 1%. The new catalytic system also allowed us to extend this chemistry to obtain excellent ortho-selectivities for unprotected anilines. The selectivities of this reaction are up to >20:1 ortho/para, while the innate selectivities for phenols and anilines are approximately 1:4 ortho/para. A series of preliminary studies revealed that the substrates require a hydrogen-bonding moiety for selectivity.
我们报告了一种利用路易斯碱性硒醚催化剂高效实现酚类化合物的邻位选择性亲电氯化反应。该硒醚催化剂的选择性与我们之前报道的双硫脲邻位选择性催化剂相当，催化剂用量低至 1%。新的催化体系还允许我们将这一化学转化扩展到未保护的苯胺，获得优异的邻位选择性。该反应的选择性高达>20:1 邻位/对位，而酚类和苯胺的固有邻位/对位选择性约为 1:4。一系列初步研究表明，底物需要氢键部分才能获得选择性。
