One-Pot Preparation of 2-Arylbenzofurans from Oximes with Diaryliodonium Triflate
摘要:
A variety of 2-arylbenzofurans were obtained in good yields by the O-arylation of oximes with diaryliodonium triflates, followed by the treatment with HCl in dioxane under warming conditions through the [3,3]-sigmatropic reaction. The present reaction is one-pot transition metal-free method for the preparation of various 2-arylbenzofurans from oximes, which are easily available from the reaction of alkyl aryl ketones with hydroxylamine
The first example of sole direct C–H bond arylation of benzo[b]furans with aryl chlorides was achieved catalyzed by a well-defined NHC-Pd(II)-Im complex. Under the suitable conditions, all reactions involving kinds of benzo[b]furans and (hetero)aryl chlorides proceeded well to give the desired C2-arylated benzo[b]furans in sole regioselectivity in acceptable to high yields, providing an efficient and
明确定义的NHC-Pd(II)-Im络合物催化了苯并[ b ]呋喃与芳基氯的唯一直接C-H键芳基化反应。在合适的条件下,所有涉及各种苯并[ b ]呋喃和(杂)芳基氯化物的反应均能顺利进行,从而以唯一的区域选择性提供所需的C2-芳基化苯并[ b ]呋喃,并以高收率接受,从而提供了有效而经济的途径用于苯并[ b ]呋喃的直接C2-H键芳基化。
A new concept of a photoremovable chiral auxiliary (PCA), based on the chiral benzoin chromophore, is introduced. This moiety can control the asymmetric formation of a Diels–Alder adduct, and then be removed in a subsequent photochemical step in high chemical and quantum yields. Selective formation of the products at up to 96% ee was observed in the presence of a Lewis acid catalyst in the case of a 2-methoxybenzoinyl chiral auxiliary.
Visible light mediated desilylative C(sp<sup>2</sup>)–C(sp<sup>2</sup>) cross-coupling reactions of arylsilanes with aryldiazonium salts under Au(<scp>i</scp>)/Au(<scp>iii</scp>) catalysis
作者:Indradweep Chakrabarty、Manjur O. Akram、Suprakash Biswas、Nitin T. Patil
DOI:10.1039/c8cc03925a
日期:——
Desilylative C(sp2)–C(sp2) cross-coupling reactions of arylsilanes with aryldiazonium salts under Au(I)/photoredox catalysis have been reported. The addition of Cu-salts as catalysts was found to be crucial for the success of this transformation.
Copper(I)-Catalyzed Coupling of Terminal Acetylenes with Aryl or Vinyl Halides
作者:D. Venkataraman、Pranorm Saejueng、Craig G. Bates
DOI:10.1055/s-2005-869893
日期:——
Synthetic protocols using copper(I) catalysts for the for- mation of diaryl acetylenes, 1,3-enynes, benzofurans and indoles are described. The acetylenic moiety is an important unit found in many compounds that are of pharmaceutical, biological and ma- terial interests. 1 Aryl acetylenes are constituent units in important conjugated polymers. 1c 1,3-Enynes are found in many biologically and pharmaceutically
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