镍催化下乙腈为氰源的芳基三氟甲磺酸酯氰化反应

Nickel-Catalyzed Cyanation of Aryl Triflates Using Acetonitrile as a Cyano Source

经典的氰化反应中多使用剧毒的金属氰源或合成复杂的有机氰源,这些氰源由于各自存在缺陷,都有一定局限性.将镍催化下低毒、廉价的乙腈作为氰源,以芳基三氟甲磺酸酯作为底物,对催化剂、配体、添加剂、温度等条件进行筛选,以物质的量分数为0.1的Ni(OTf)_(2)作为催化剂,物质的量分数为0.1的1,3-双(二苯基膦)丙烷作为配体,物质的量分数为2的Zn作为还原剂,物质的量分数为0.2的Zn(OTf)_(2)作为添加剂,0.7 mL乙腈作为溶剂,氮气保护下,100℃反应60 h,成功实现芳基腈的高效合成.在该反应条件下,给电子取代基的底物展现出高效的反应性.该方法第一次实现镍催化下芳基三氟甲磺酸酯的氰化反应,成功使用绿色、经济的乙腈溶剂作为该反应的氰源.

In classic cyanation reactions,toxic metal cyanide sources or complex organic cyanide sources are often used.Therefore,it is particularly important to develop a green and economical cyano source.Initially,4-biphenylyl trifluoromethanesulfonate is chosen as the model substrate.Through extensive screening of catalysts,ligands,additives,reductant,temperature and other conditions,the optimal conditions are obtained(Ni(OTf)_(2),1,3-bis(diphenyphosphino)propane,Zn(OTf)_(2),Zn with a mole fraction of 0.1,0.1,0.2,2,respectively,0.7 mL CH_(3)CN,N_(2),60 h,100℃).Subsequently,the generation and limitations of the substrates are studied under optimal conditions.It is found that substrates bearing electron-donating substituents exhibit an excellent efficiency for the cyanation of aryl trifluoromethanesulfonates.The cyanation of aryl trifluoromethanesulfonates is first realized under the catalysis of nickel with acetonitrile as a green and economical cyano source.