Rhodium-catalyzed C2 and C4 C–H activation/annulation of 3-(1H-indol-3-yl)-3-oxopropanenitriles with internal alkynes: a facile access to substituted and fused carbazoles
作者:Tao Zhou、Bin Li、Baiquan Wang
DOI:10.1039/c7cc02808c
日期:——
annulation reactions of 3-(1H-indol-3-yl)-3-oxopropanenitriles with internal alkynes have been developed. A series of substituted carbazoles and 4H-oxepino[2,3,4,5-def]carbazoles, through a formal Rh(III)-catalyzed (4+2) cycloaddition with an alkyne and tandem (4+2) and (5+2) cycloaddition with two molecules of alkynes, were obtained. The reactions involved sequential cleavage of C(sp2)–H/C(sp3)–H bonds
已经开发了铑催化的3-(1 H-吲哚-3-基)-3-氧代丙烷腈与内部炔烃的氧化环化反应。通过带有炔烃和串联(4 + 2)的正式Rh(III)催化的(4 + 2)环加成反应,生成一系列取代的咔唑和4 H -oxepino [2,3,4,5- def ]咔唑获得5 + 2)与两个炔烃分子的环加成。反应包括第一步中的C(sp 2)–H / C(sp 3)–H键的顺序裂解和炔烃的环化,以及C(sp 2)–H / O–H键的连续裂解和环化的顺序。第二步是与另一个炔烃 4 H -oxepino [2,3,4,5- def中的一些]咔唑产品在固态时表现出强烈的荧光。