Pyrrolodiazines. 6. Palladium-Catalyzed Arylation, Heteroarylation, and Amination of 3,4-Dihydropyrrolo[1,2-<i>a</i>]pyrazines
作者:Isabel Castellote、Juan J. Vaquero、Javier Fernández-Gadea、Julio Alvarez-Builla
DOI:10.1021/jo048898o
日期:2004.12.1
The palladium-catalyzed Suzuki cross-coupling reaction of arylboronic acids and 6-bromo- and 6,8-dibromo-3,4-dihydropyrrolo[1,2-a]pyrazines afforded 6-substituted and 6,8-disubstituted 3,4-dihydropyrrolo[1,2-a]pyrazines in good yields. Stille and Negishi coupling reactions have been used to prepare 6-heteroaryl-substituted derivatives in moderate yields by employing heteroaryl halides and 6-metalated
芳基硼酸与6-溴-和6,8-二溴-3,4-二氢吡咯并[1,2- a ]吡嗪的钯催化的Suzuki交叉偶联反应得到6-取代的和6,8-二取代的3,4 -二氢吡咯并[1,2- a ]吡嗪产率高。Stille和Negishi偶联反应已用于通过采用杂芳基卤化物和6-金属化3,4-二氢吡咯并[1,2- a ]吡嗪作为反应伙伴,以中等收率制备6-杂芳基取代的衍生物。在钯催化剂Pd 2(dba)3存在下,在6-溴-1-苯基-3,4-二氢吡咯并[1,2- a ]吡嗪的C-6位处也引入了多种环状仲胺。结合BINAP作为配体。该胺化反应是在吡咯环上这种钯催化的转化的少数报道的实例之一,尽管该反应不能扩展到较少的亲核胺。