An iridium-catalyzed annulation of chalcones with sulfonylazides via cascade C–H amidation and intramolecular aza-Michael addition was developed, affording a variety of 2-aryl-2,3-dihydro-4-quinolones in moderate to good yields. This reaction features easy operation, readily available starting materials, and the cascade formation of two C–N bonds in one pot.
Chiral aldehyde catalysis is uniquely suitable for the direct asymmetric α-functionalization of N-unprotected amino acids, because aldehydes can reversibly form imines. However, there have been few successful reports of these transformations. In fact, only chiral aldehyde catalyzed aldol reactions of amino acids and alkylation of 2-amino malonates have been reported with good chiral induction. Here
1‐Arylvinyl formates as a kind of new CO surrogate have been explored for the first time. Most of the known CO precursors usually produce undesired residuals, which have to be removed. In this strategy, after CO release, the in situ generated acetophenones from 1‐arylvinyl formates can be successfully applied as a good ketone source in the synthesis of chalcones with benzaldehydes via a palladium‐catalyzed
Palladium-Catalyzed Coupling Reactions: Carbonylative Heck Reactions To Give Chalcones
作者:Xiao-Feng Wu、Helfried Neumann、Matthias Beller
DOI:10.1002/anie.201002155
日期:——
Chalcones made easy: CarbonylativeHeckreactions of aryl and alkenyl triflate derivatives with carbon monoxide and aromatic olefins proceed in the presence of palladium catalysts (see scheme; dppp=1,3‐bis(diphenylphosphino)propane, Tf=triflate; R=aryl, vinyl). With this process, the gap between the Suzuki and Sonogashira carbonylativereactions is finally bridged.
轻松实现Chalcones:在钯催化剂的存在下,芳基和链烯基三氟甲磺酸酯衍生物与一氧化碳和芳族烯烃的羰基Heck反应进行(参见方案; dppp = 1,3-双(二苯基膦基)丙烷,Tf =三氟甲磺酸酯; R =芳基乙烯基塑料)。通过这个过程,Suzuki和Sonogashira羰基化反应之间的差距最终得以弥合。
Synthesis of α,β-unsaturated ketones from alkynes and aldehydes over Hβ zeolite under solvent-free conditions
作者:Naresh Mameda、Swamy Peraka、Srujana Kodumuri、Durgaiah Chevella、Rammurthy Banothu、Vasu Amrutham、Narender Nama
DOI:10.1039/c6ra11593d
日期:——
A facile Hβ zeolite-catalyzed strategy has been successfully developed for the synthesis of α,β-unsaturated ketones from alkynes and aldehydes under solvent-free conditions. The reaction proceeds via tandem hydration/condensation of alkynes with aldehydes to afford a range of α,β-unsaturated carbonyls in good to excellent yields.