A catalytic amount of triarylaminium salt is demonstrated to be an efficient initiator for oxidative Mannich reaction of tertiary amines and nonactivated ketones under mild neutral conditions. Air is essential for this reaction and acts as a terminal oxidant. Metal catalysts, acid or base additives, and stoichiometric amounts of chemical oxidants are all avoided in this methodology. Six examples of
A novel bifunctional organic sponge photocatalyst can enable the efficient coupling of tertiary amines with ketones in water. The asymmetric transformation can be also achieved by using this sponge photocatalyst.
Metal-Free Oxidation/C(sp<sup>3</sup>)H Functionalization of Unactivated Alkynes Using Pyridine-<i>N</i>-Oxide as the External Oxidant
作者:Dian-Feng Chen、Zhi-Yong Han、Yu-Ping He、Jie Yu、Liu-Zhu Gong
DOI:10.1002/anie.201205062
日期:2012.12.3
3‐Dihydroquinolin‐4(1H)‐ones are obtained in moderate to good yields (40–84 %, see scheme) in a metal‐free oxidation/C(sp3)Hfunctionalization of unactivated aryl alkynes. 2,6‐Dichloropyridine‐N‐oxide is used as an externaloxidant. In the reaction, a Brønsted acid, not a metal, plays a key role in the triple CC bond activation.
Mild Metal-Free Intramolecular Oxidative Alkylation of a C<sub><i>sp</i>3</sub>H Bond Adjacent to a Nitrogen Atom: A Versatile Approach to Ring-Fused Tetrahydroquinolines
作者:Gen Zhang、Shoulei Wang、Yunxia Ma、Weidong Kong、Rui Wang
DOI:10.1002/adsc.201200731
日期:2013.3.25
A metal‐free intramolecularoxidative cross‐coupling reaction for the constructing Csp3Csp3 bonds mediated by 2,3‐dichloro‐5,6‐dicyanobenzoquinone (DDQ) under mild conditions was realized for the first time. This novel strategy provides a simple, efficient, and environmentally friendly access to diverse ring‐fused tetrahydroquinoline derivatives.
Unprecedented constructions of C═Cdouble bonds have been achieved by Ir-catalyzed intramolecular dehydrogenative and dehydrative cross-coupling of tertiary amines and ketones. The reactions are proposed to proceed via an Ir-mediated C–H activation mechanism.