Microwave-Accelerated Iridium-Catalyzed Borylation of Aromatic C−H Bonds
作者:Peter Harrisson、James Morris、Todd B. Marder、Patrick G. Steel
DOI:10.1021/ol901306m
日期:2009.8.20
accelerates the Ir-catalyzed C−H borylation of aromatic substrates when compared with reactions carried out at the same temperature under standard heating conditions. Application to a one-pot single solvent process for tandem C−H borylation/Suzuki−Miyauracross-coupling sequences using microwave-accelerated reactions gives fast and efficient access to a wide range of biaryl and heterobiaryl compounds.
Ir-Catalyzed Functionalization of 2-Substituted Indoles at the 7-Position: Nitrogen-Directed Aromatic Borylation
作者:Sulagna Paul、Ghayoor A. Chotana、Daniel Holmes、Rebecca C. Reichle、Robert E. Maleczka,、Milton R. Smith
DOI:10.1021/ja0631652
日期:2006.12.1
Ir-catalyzed borylation of 2-substituted indoles selectively yields 7-borylated products in good yields. N-Protection, required for previous functionalizations of 2-substituted indoles, is unnecessary.
2-取代吲哚的 Ir 催化硼酸化选择性地以良好的产率产生 7-硼酸化产物。2-取代吲哚的先前功能化所需的N-保护是不必要的。
Iridium-Catalyzed, Silyl-Directed Borylation of Nitrogen-Containing Heterocycles
作者:Daniel W. Robbins、Timothy A. Boebel、John F. Hartwig
DOI:10.1021/ja1006405
日期:2010.3.31
Selective methods for the functionalization of indoles and other nitrogen heterocycles would provide access to the core structures of many natural products and pharmaceuticals. Although there are many methods and strategies for the synthesis of substituted indoles or functionalization of the azole ring, strategies for the selective functionalization of the benzo-fused portion of the indole skeleton, particularly the 7-position, are less common. We report a one-pot, iridium-catalyzed, silyl-directed C-H borylation of indoles at the 7-position. This process occurs in high yield with a variety of substituted indoles, and conversions of the 7-borylindole products to 7-aryl-, 7-cinnamyl-, and 7-haloindoles are demonstrated. The Ir-catalyzed, silyl-directed C-H borylation also occurs with several other nitrogen heterocycles, including carbazole, phenothiazines, and tetrahydroquinoline. The utility of this methodology is highlighted by the one-pot synthesis of a member of the pyrrolophenanthridone class of alkaloid natural products.