Cascade Palladium-Catalyzed Direct Intramolecular Arylation/Alkene Isomerization Sequences: Synthesis of Indoles and Benzofurans
作者:Myriam Yagoubi、Ana C. F. Cruz、Paula L. Nichols、Richard L. Elliott、Michael C. Willis
DOI:10.1002/anie.201004097
日期:2010.10.18
One route, two cycles: A palladium‐catalyzed intramoleculardirectarylation reaction combined with an isomerization step provided a straightforward synthetic route to both indoles and benzofurans (see scheme). Isolation and functionalization of intermediate alkene isomers allowed the formation of variants having substituents remote from the core.
The selective oxidation of C2-alkyl-substituted indoles to 3-oxindole and the selective C–H oxygenation or amination of C2,C3-dialkyl-substituted indoles at C2 are reported under mild conditions. The position of the alkyl substitution on the indole directs the reaction to different pathways under similar conditions.
B(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub>-Catalyzed Direct C3 Alkylation of Indoles and Oxindoles
作者:Shyam Basak、Ana Alvarez-Montoya、Laura Winfrey、Rebecca L. Melen、Louis C. Morrill、Alexander P. Pulis
DOI:10.1021/acscatal.0c01141
日期:2020.4.17
The direct C3 alkylation of indoles and oxindoles is a challenging transformation, and only a few direct methods exist. Utilizing the underexplored ability of triaryl boranes to mediate the heterolytic cleavage of α-nitrogen C–H bonds in amines, we have developed a catalytic approach for the direct C3 alkylation of a wide range of indoles and oxindoles using amine-based alkylating agents. We also employed
One-pot, three-component Fischer indolisation–<i>N</i>-alkylation for rapid synthesis of 1,2,3-trisubstituted indoles
作者:Christopher A. Hughes-Whiffing、Alexis Perry
DOI:10.1039/d0ob02185g
日期:——
A one-pot, three-component protocol for the synthesis of 1,2,3-trisubstituted indoles has been developed, based upon a Fischer indolisation–indole N-alkylation sequence. This procedure is very rapid (total reaction time under 30 minutes), operationally straightforward, generally high yielding and draws upon readily available building blocks (aryl hydrazines, ketones, alkyl halides) to generate densely