Intramolecular activation of strong Si–O bonds by gold(<scp>i</scp>): regioselective synthesis of 3-bromo-2-silylbenzofurans
作者:Paula Fernández-Canelas、Rubén Miguélez、Eduardo Rubio、José Manuel González、Pablo Barrio
DOI:10.1039/d2cc03060h
日期:——
of one of the strongest bonds in organic chemistry (Si–O), strategically placed at the ortho-position. In this way, the synthesis of 3-bromo-2-silylbenzofuranes is achieved in good yields. Several substituents with different electronic properties and substitution patterns are well tolerated on the tethering aromatic ring as well as a number of silyl groups on the O-atom. A preliminary mechanistic study
金-亚乙烯基配合物的高反应性,由相应的 1-溴炔烃的 [1,2]-溴转移原位产生,允许激活有机化学中最强的键之一 (Si-O),战略性地放置在邻位。这样,3-溴-2-甲硅烷基苯并呋喃的合成以良好的收率实现。几个具有不同电子特性和取代模式的取代基在束缚芳环上以及在 O 原子上的许多甲硅烷基上都具有良好的耐受性。初步的机理研究与金亚乙烯基中间体的参与是相容的。通过正交C-C键形成转化初步展示了所得支架的合成适用性。
Egami, Hiromichi; Katsuki, Tsutomu, Journal of the American Chemical Society, 2009, vol. 131, p. 6082 - 6083
作者:Egami, Hiromichi、Katsuki, Tsutomu
DOI:——
日期:——
Enantioenriched Synthesis of <i>C</i><sub>1</sub>-Symmetric BINOLs: Iron-Catalyzed Cross-Coupling of 2-Naphthols and Some Mechanistic Insight
Highly enantioselective aerobic oxidative cross-coupling of 2-naphthols with broad substrate scope was achieved using an iron(salan) complex as the catalyst. Enantiomeric excesses of the products ranged from 87 to 95%. The scope of the cross-coupling reaction was found to be different from that of the homocoupling reaction under the same reaction conditions.
Nickel-Catalyzed Boron Insertion into the C2–O Bond of Benzofurans
Treatment of benzofurans with bis(pinacolato)diboron and Cs2CO3 under nickel-NHC catalysis resulted in the insertion of a boron atom into the C2-O bond of benzofurans to afford the corresponding oxaborins. The scope of benzofuran substrates is wide, and the reactions proceeded without loss of functional groups such as fluoro, methoxy, and ester that are potentially reactive under nickel catalysis.
Dihydrobiphenylenes through Ruthenium-Catalyzed [2+2+2] Cycloadditions of<i>ortho</i>-Alkenylarylacetylenes with Alkynes
作者:Silvia García-Rubín、Carlos González-Rodríguez、Cristina García-Yebra、Jesús A. Varela、Miguel A. Esteruelas、Carlos Saá
DOI:10.1002/anie.201309496
日期:2014.2.10
A new synthetic route to dihydrobiphenylenes has been developed. The process involves a mild RuII‐catalyzed [2+2+2] dimerization of ortho‐alkenylarylacetylenes or its more versatile variant, the Ru‐catalyzed [2+2+2] cycloaddition of ortho‐ethynylstyrenes with alkynes. Mechanistic aspects of this [2+2+2] cycloaddition are discussed.