Phosphine Ligand‐Free Ruthenium Complexes as Efficient Catalysts for the Synthesis of Quinolines and Pyridines by Acceptorless Dehydrogenative Coupling Reactions
作者:Bin Guo、Tian‐Qi Yu、Hong‐Xi Li、Shi‐Qi Zhang、Pierre Braunstein、David J. Young、Hai‐Yan Li、Jian‐Ping Lang
DOI:10.1002/cctc.201900435
日期:2019.5.20
corresponding ligand in EtOH. Five Ru(II) complexes [LRu(DMSO‐κS)Cl2] (2 a: L=L1; 2 b: L=L2; 2 c: L=L3; 2 d: L=L4; 2bMe: L=L2Me) were formed by reducing the corresponding Ru(III) complex in refluxing EtOH. The latter complexes could also be prepared directly by refluxing Ru(DMSO)4Cl2 with the corresponding ligand in EtOH. These Ru(III) and Ru(II) complexes, especially 1 b/2 b, exhibited high catalytic
Mn(III)-Mediated Reactions of Cyclopropanols with Vinyl Azides: Synthesis of Pyridine and 2-Azabicyclo[3.3.1]non-2-en-1-ol Derivatives
作者:Yi-Feng Wang、Shunsuke Chiba
DOI:10.1021/ja905110c
日期:2009.9.9
to the formation of 2-azabicyclo[3.3.1]non-2-en-1-ol derivatives using a catalytic amount of Mn(acac)(3). These reactions may be initiated by a radicaladdition of beta-keto radicals, generated by the one-electron oxidation of cyclopropanols, to vinyl azides to give iminyl radicals, which would cyclize with the intramolecular carbonyl groups. In addition, versatile transformations of 2-azabicyclo[3.3
Mn(III)-mediated formal [3+3]-annulation has been developed using readily available vinylazides and cyclopropanols with a wide range of substituents. Vinylazides were successfully applied as a three-atom unit including one nitrogen to prepare pyridines and δ-lactams by the reactions with monocyclic cyclopropanols as well as to construct 2-azabicyclo[3.3.1] and 2-azabicyclo[4.3.1] frameworks with
Copper-catalyzed direct C–H arylation of pyridineN-oxides with arylboronic esters for the one-pot synthesis of 2-arylpyridines without an additional reductant.
Synthesis of Asymmetrical 2,6-Diarylpyridines from Linear α,β,γ,δ-Unsaturated Ketones by Addition of Ammonium Formate Followed by Annulation
作者:Yejun Gao、Rener Chen、Yongmin Ma
DOI:10.1055/s-0037-1610725
日期:2019.10
established for the synthesis of asymmetrical 2,6-diarylpyridines by cyclization of α,β,γ,δ-unsaturated ketones with ammonium formate under air atmosphere. The reaction is metal-free and operationally convenient from readily available starting materials. Thirty-three examples have been presented, most of which show good yields. A simple and efficient method has been established for the synthesis of asymmetrical