A photoredox and Brønsted acid synergistically catalyzed cross‐dehydrogenative C−Ocouplingreaction is developed in which isochroman peroxyacetals are formed through sp3 C−H bond peroxidation. The reported method is characterized by its extremely mild reaction conditions, excellent yields, and broad substrate scope. An oxocarbenium ion p‐chlorobenzenesulfonate was speculated to be the reactive intermediate
DDQ-mediated Direct C(sp<sup>3</sup>)H Cyanation of Benzyl Ethers and 1,3-Diarylpropenes under Solvent- and Metal-free Conditions
作者:Shanshan Kong、Lingqiong Zhang、Xiaoli Dai、Lianzhi Tao、Chunsong Xie、Lei Shi、Min Wang
DOI:10.1002/adsc.201500096
日期:2015.8.10
A directcyanation of benzylethers and 1,3‐diarylpropenes with TMSCN was performed under solvent‐ and metal‐free conditions. This oxidative cross dehydrative coupling (CDC) reaction was promoted by 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ) and provided rapid access to a broad range of nitriles in good to excellent yields.
A phosphane‐catalyzed [3+3] annulation of azomethineimines with ynones has been developed. Under mild reaction conditions, the reaction proceeds smoothly to afford tricyclic dinitrogen‐fused heterocyclic compounds in moderate to excellent yields with moderate to excellent stereoselectivies. Using a chiral phosphine as the catalyst, the reaction could work to give the cycloadduct in moderate yield
A ligand-free iron-catalyzed method for the oxygenation of benzylic sp3 C–H bonds by molecular oxygen (1 atm) using a thiylradical as a cocatalyst has been developed. This transformation provides a facile access to amides, esters and ketones from readily accessible corresponding amines, ethers and alkanes. It features high regioselectivity, mild oxidative conditions and excellent functional group