Błocka Aleksandra, Woźnicki Paweł, Stankevič Marek, Chaładaj Wojciech
Institute of Organic Chemistry, Polish Academy of Sciences Kasprzaka 44/52 01-224 Warsaw Poland
Department of Organic Chemistry, Faculty of Chemistry, Marie Curie-Skłodowska University in Lublin Gliniana 33 20-614 Lublin Poland.
RSC Adv. 2019 Dec 3;9(68):40152-40167. doi: 10.1039/c9ra08002c. eCollection 2019 Dec 2.
We report an efficient protocol for tandem Pd-catalyzed intramolecular addition of active methylene compounds to alkynes, followed by subsequent cross-coupling with (hetero)aryl bromides and chlorides. The reaction proceeds under mild conditions, providing excellent functional group tolerance, including unprotected OH, NH groups, enolizable ketones, or a variety of heterocycles. Mechanistic studies point towards a catalytic cycle involving oxidative addition, intramolecular nucleophilic addition to the Pd(ii)-activated alkyne, and reductive elimination, with 5- cyclization being the rate limiting step.
我们报道了一种高效的串联反应方案，该方案通过钯催化活性亚甲基化合物与炔烃进行分子内加成，随后与（杂）芳基溴化物和氯化物进行交叉偶联。该反应在温和条件下进行，对官能团具有出色的耐受性，包括未保护的羟基、氨基、可烯醇化的酮或各种杂环。机理研究表明催化循环涉及氧化加成、对钯（II）活化炔烃的分子内亲核加成以及还原消除，其中5-环化是速率限制步骤。
