A thioether-directed Rh(III)-catalyzed C4 selective C–H alkenylation of indoles via the formation of 5-membered metallacycle intermediates is reported. This protocol allows a wide functional group compatibility and broad substrate scope. The directing group can be readily removed or transformed into other functional groups after the C–H functionalization event. The catalytic method is also applicable
据报道通过五元金属环中间体形成硫醚导向的Rh(III)催化的吲哚的C4选择性C–H链烯基化。该协议允许广泛的官能团兼容性和广泛的底物范围。在C–H官能化事件发生后,可以很容易地将导向基团除去或转化成其他官能团。该催化方法也适用于涉及苯并[ b ]噻吩和苯并[ b ]呋喃骨架的相关杂环体系。
Iridium‐Catalyzed Direct C4‐ and C7‐Selective Alkynylation of Indoles Using Sulfur‐Directing Groups
past century, and extensive studies have been conducted to establish practical synthetic methods for their derivatives. In particular, selective functionalization of the poorly reactive benzenoid core over the pyrrole ring has been a great challenge. Reported herein is an iridium‐catalyzed direct alkynylation of the indole C4‐ and C7‐positions with the assistance of sulfur directing groups. This transformation
Site-selective direct functionalization of an indole benzenoid core has been a great challenge due to its inherently poor reactivity. We herein demonstrate an iridium-catalyzed C4-selective acylmethylation of indoles using alpha-carbonyl sulfoxonium ylides as carbene precursors. This method exhibits high efficiency and broad functional group compatibility. The directing group was easily removed or converted to other functionalities after the catalysis. The potential synthetic utility of the coupling products was highlighted by constructing medium-sized polycyclic indoles.
A Practical Regioselective Synthesis of Alkylthio- or Arylthioindoles without the Use of Smelly Compounds Such as Thiols
convenient method for the synthesis of 3-methylthioindoles has been established which does not use smelly compounds such as thiol derivatives. The method, which introduces an alkyl- or arylthio-group into the C(3)-position of the indole skeleton, was extended to the direct introduction of a methylthio or bromo group at the C(2)-position using 3-methylthioindoles. No dimerization occurred, and the reaction
way: A formal [4+2] cycloaddition between various cyclobutanones and indoles proceeded efficiently under Lewis acid catalysis (see scheme; PG = protecting group). The regioselectivity of the reaction could be controlled in such a way that each of the two possible regioisomers of a cycloaddition product could be synthesized selectively. The usefulness of this reaction for the total synthesis of hydrocarbazole