Palladium(II)-Catalyzed Annulation of Alkynes with 2-(Cyanomethyl)phenylboronates Leading to 3,4-Disubstituted 2-Naphthalenamines
作者:Hirokazu Tsukamoto、Taishi Ikeda、Takayuki Doi
DOI:10.1021/acs.joc.5b02378
日期:2016.3.4
palladium(II) complexes catalyze the annulation of internal alkynes with 2-(cyanomethyl)phenylboronates to provide 3,4-disubstituted-2-naphthalenamines in good yields. The annulation reaction proceeds under mild and neutral conditions and requires methanol as an essential solvent. In addition to symmetrical alkynes, unsymmetrical alkynes substituted by aryl, alkyl, and alkynyl groups participate in
1,2-双(二苯基膦基)乙烷(dppe)连接的钯(II)配合物催化内部炔烃与2-(氰基甲基)苯基硼酸酯的环化反应,从而以良好的收率提供3,4-二取代的-2-萘胺。环化反应在温和和中性条件下进行,需要甲醇作为必要溶剂。除对称炔烃外,被芳基,烷基和炔基取代的不对称炔烃也参与环化反应,得到相应的带有吸电子sp 2的2-萘胺。-和sp-carbons优先位于C-3位置。在硼酸酯中包括在氰基甲基部分上的烷基或烷氧基和在苯环上的卤素原子的取代基与反应条件相容。通过用硼酸酯和炔烃插入钯(II)配合物进行金属转移,然后将生成的烯基钯(II)亲核加成到分子内氰基中来进行环化。化学计量反应表明,甲醇溶剂对于重金属化和催化剂再生均有效。