copper-catalyzed C–N bond cleavage of aromatic methylamines was developed to construct pyridine derivatives. With neat conditions and facile operation, the fragment-assembling strategy affords a broad range of 2,4,6-trisubstituted pyridines in up to 95% yield from simple and readily available starting materials. Interestingly, when pyridin-2-yl methylamine was employed as the substrate, α-alkylation reaction
New hydroacylation catalysts: Highly electron‐rich N‐heterocyclic carbenes (NHCs) facilitate the intermolecular hydroacylation of unstrained olefins. This unprecedented organocatalytic coupling joins simple and abundant aldehydes and styrenes to yield valuable ketone products. EWG=electron‐withdrawing group, EDG=electron‐donating group.
Ñ EW ħ ydroacylation Ç atalysts:富电子高度N-杂环卡宾(NHC的)无应变促进烯烃的分子间加氢酰化。这种前所未有的有机催化偶合使简单而丰富的醛和苯乙烯结合在一起,可制得有价值的酮产品。EWG =吸电子基团,EDG =给电子基团。
Efficient ruthenium-catalyzed α-alkylation of ketones using pyridyl methanols
By employing an easily available [Ru(p-cymene)Cl-2](2)/Xantphos/t-BuOK catalyst system, the alpha-alkylation of ketones was demonstrated by using pyridyl methanol as the alkylating reagents. The synthetic protocol allows synthesizing a wide range of alpha-pyridyl methylated ketones in reasonable to excellent isolated yields with high atom-efficiency. The transformation is operationally simple, the substrate scope is wide, and the starting materials are readily-available. There is no need for addition of alkenes as the hydrogen receptors or the use of stoichiometric amount of base. (C) 2013 Elsevier Ltd. All rights reserved.