Iodine/Palladium Approaches to the Synthesis of Polyheterocyclic Compounds
作者:Saurabh Mehta、Richard C. Larock
DOI:10.1021/jo902639f
日期:2010.3.5
A simple, straightforward strategy for the synthesis of polyheterocyclic compounds (PHCs) is reported, which involves iterative cycles of palladium-catalyzed Sonogashira coupling, followed by iodocyclization using I2 or ICl. A variety of heterocyclic units, including benzofurans, benzothiophenes, indoles, and isocoumarins, can be efficiently incorporated under mild reaction conditions. In addition
报道了一种简单、直接的合成多杂环化合物 (PHC) 的策略,该策略涉及钯催化的 Sonogashira 偶联的迭代循环,然后使用 I 2或 ICl进行碘环化。多种杂环单元,包括苯并呋喃、苯并噻吩、吲哚和异香豆素,可以在温和的反应条件下有效地结合。此外,这种策略的变体提供了各种连接和融合的 PHC。
p-Toluenesulfonic acid-promoted selective functionalization of unsymmetrical arylalkynes: a regioselective access to various arylketones and heterocycles
Regioselective hydration of a wide range of internalalkynes has been afforded in high to good yields by using PTSA in EtOH. The scope of the reaction of alkynes has been delineated. Arylaliphatic alkynes and diarylalkynes were regioselectively hydrated in good to excellent yields and short reaction times when the reaction was achieved under microwave irradiation. Moreover, diarylalkynes, arylenynes
MPHT-Promoted Bromocyclization of ortho-Substituted Arylalkynes: Application to the Synthesis of 2-Substituted 3-Bromobenzofurans and -Benzo[b]thiophenes
A convenient and general approach to the synthesis of 2‐substituted 3‐bromobenzofurans and ‐benzothiophenes was developed. The procedure is based on the cyclization of ortho‐substituted arylalkynes in the presence of N‐methylpyrrolidin‐2‐one hydrotribromide (MPHT) as a soft and easy‐to‐handle electrophilic brominating reagent. Under mild reaction conditions, MPHT promoted the bromocyclization of various