Mechanistic Insights on Orthogonal Selectivity in Heterocycle Synthesis
作者:Arun Maji、Yernaidu Reddi、Raghavan B. Sunoj、Debabrata Maiti
DOI:10.1021/acscatal.8b02537
日期:2018.11.2
Recently, we have developed a method for catalytic regioselectivesynthesis of 2-substituted and 3-substituted benzofurans starting from phenols. The choice of reacting partner, olefin versus α,β-unsaturated acid, is critical to dictate the isomeric product formation. Instances are known where these olefinic partners did not complement each other and yield a similar outcome. In the current work, we
Triple CH functionalization: Palladium‐catalyzed synthesis of benzofurans and coumarins by reacting phenols and unactivated olefins is described. The reaction comprises sequential CH functionalization and shows diverse functional group compatibility. Preliminary mechanistic studies shed light into the possible mechanisms.
paper describes the preparation of indoles, azaindoles and benzofurans in pure water by using a new heterogeneous Pd-Cu/C catalyst through a cascade Sonogashira alkynylation-cyclization sequence. Details of the optimization studies and the substrate scope are discussed. This procedure allows the preparation of heterocycles with good yields and is tolerant to a wide variety of functional groups.
Pd-Catalyzed Tandem Chemoselective Synthesis of 2-Arylbenzofurans using Threefold Arylating Triarylbismuth Reagents
作者:Maddali L. N. Rao、Deepak N. Jadhav、Priyabrata Dasgupta
DOI:10.1002/ejoc.201201314
日期:2013.2
A tandemchemoselectivesynthesis of 2-arylbenzofurans was accomplished from o-hydroxy-gem-(dibromovinyl)benzenes and BiAr3 reagents under palladium-catalyzed conditions. This unique and synthetically valuable strategy proceeds through three consecutive coupling reactions involving triarylbismuthreagents and provides 2-arylbenzofuran products in high yields.
Transition-metal-free base catalyzed intramolecular cyclization of 2-ynylphenols for efficient and facile synthesis of 2-substituted benzo[<i>b</i>]furans
作者:Yong Liu、Tao Lu、Wei-Fang Tang、Jian Gao
DOI:10.1039/c8ra03882a
日期:——
A transition-metal-free basecatalyzedintramolecular cyclization of 2-ynylphenols was developed for the facile synthesis of 2-substituted benzo[b]furans. Various 2-aryl and 2-alkyl substituted benzo[b]furans can be obtained with good to excellent yields using readily available Cs2CO3 as the catalyst under mild reaction conditions. The broad substrates scope and the typical maintenance of vigorous
开发了一种无过渡金属碱催化的 2-炔基酚分子内环化,用于简便合成 2-取代的苯并[ b ]呋喃。使用容易获得的 Cs 2 CO 3作为催化剂,在温和的反应条件下,可以以良好至优异的收率获得各种 2-芳基和 2-烷基取代的苯并[ b ]呋喃。广泛的底物范围和克级高效效率的典型维持使该协议成为合成 2-取代苯并[ b ]呋喃衍生物的潜在实用方法。