has been achieved using tertiaryamines as both methylene (-CH2-) transfer and arylmethylation agents and K2S2O8 as a convenient oxidant. The key feature of this protocol is the utilisation of K2S2O8 as an inexpensive and easy to handle radical surrogate that can effectively promote the reaction, leading to the formation of C(sp2)–C(sp3)–C(sp2) bonds via sp3 C–H bond oxidation in water at room temperature
Ruthenium-Catalyzed Alkylation of Indoles with Tertiary Amines by Oxidation of a sp<sup>3</sup>CH Bond and Lewis Acid Catalysis
作者:Ming-Zhong Wang、Cong-Ying Zhou、Man-Kin Wong、Chi-Ming Che
DOI:10.1002/chem.200902387
日期:2010.5.17
catalysts for directC‐3 alkylation of indoles, giving the desired products in high yields (up to 82 % based on 60–95 % substrate conversions). These ruthenium compounds catalyze oxidative couplingreactions of a wide variety of anilines and indoles bearing electron‐withdrawing or electron‐donating substituents with high regioselectivity when using tBuOOH as an oxidant, resulting in the alkylation of N‐arylindoles
Metal and acid-free visible light-induced Friedel-Crafts C3-alkylation reactions of indolederivatives were developed using N,N-dimethylanilines as the carbon source. A cheap and readily available organic dye, Rose Bengal, was applied as the photocatalyst. This environmentally friendly transformation afforded C3-alkylated indoles in moderate to good yields under mild conditions.