Zn<sup>II</sup>- and Au<sup>I</sup>-Catalyzed Regioselective Hydrative Oxidations of 3-En-1-ynes with Selectfluor: Realization of 1,4-Dioxo and 1,4-Oxohydroxy Functionalizations
作者:Appaso Mahadev Jadhav、Sagar Ashok Gawade、Dhananjayan Vasu、Ramesh B. Dateer、Rai-Shung Liu
DOI:10.1002/chem.201304322
日期:2014.2.10
Catalytic 1,4‐dioxo functionalizations of 3‐en‐1‐ynes to (Z)‐ and (E)‐2‐en‐1,4‐dicarbonyl compounds are described. This regioselective difunctionalization was achieved in one‐pot operation through initial alkyne hydration followed by in situ Selectfluoroxidation. The presence of pyridine alters the reaction chemoselectivity to give 4‐hydroxy‐2‐en‐1‐carbonyl products instead. A cooperative action of
β-unsaturated ketones could be obtained by palladium-catalyzed ring-opening of mono-substituted cyclopropyl ketones efficiently and systematically. (E)-1-Arylbut-2-en-1-ones were generated from aryl cyclopropyl ketones stereoselectively in yields of 23–89% by the Pd(OAc)2/PCy3 catalytic system. The reaction exhibited stereoselectivity (only E products were found) and was suitable for both phenyl and
在此,我们报道通过钯催化的单取代环丙基酮的开环可以有效且系统地获得α,β-不饱和酮。( E )-1-Arylbut-2-en-1-ones 通过 Pd(OAc) 2 /PCy 3催化体系由芳基环丙基酮立体选择性生成,收率为 23-89% 。该反应表现出立体选择性(仅发现E产物)并且适用于苯基和杂芳基环丙基酮。
Aldol/Brook/Carbon Skeletal Rearrangement Cascade Reactions of β‐Silyl Ketones with Aldehydes
Alkenylation of aldehydes with β-silyl ketones proceeded to afford β,γ-unsaturated ketones with skeletal rearrangement. The reaction mechanism involved tandem aldol/[1,4]-Brook/1,2-addition/ring cleavage of cyclopropane. [1,4] Brook rearrangement took place with complete inversion of configuration at the carbon center.
Using Rh(III)-Catalyzed C–H Activation as a Tool for the Selective Functionalization of Ketone-Containing Molecules
作者:Mélissa Boultadakis-Arapinis、Matthew N. Hopkinson、Frank Glorius
DOI:10.1021/ol500258q
日期:2014.3.21
Due to the strong potential of C H activation in many areas of organic chemistry, the use of a pre-existing carbonyl group for the installation of a directing group to enable selective and predictable alpha-alkenylation with activated olefins as coupling partners is described. This Heck-type reaction would then lead either to beta,gamma-unsaturated ketones or to variously substituted 1,4-butadienes depending on the conditions used for the cleavage of the directing group.