Tandem Addition β-Lithiation−Alkylation Sequence on α,β-Unsaturated Aldehydes
作者:Norma Sbarbati Nudelman、Graciela V. García
DOI:10.1021/jo005698d
日期:2001.2.1
isotopic exchange reactions and trapping of two intermediates, provide clues on the several mechanistic steps of this new reaction. Extended studies revealed that beta-alkyl-substituted alpha,beta-unsaturated aldehydes and aliphatic lithium reagents did not afford good yields of the tandem reaction products, while aromatic lithium reagents gave good results. The aggregation features of the aryllithium
Highly Regio- and Enantioselective Reductive Coupling of Alkynes and Aldehydes via Photoredox Cobalt Dual Catalysis
作者:Yan-Lin Li、Shi-Qi Zhang、Jie Chen、Ji-Bao Xia
DOI:10.1021/jacs.1c03527
日期:2021.5.19
A Co-catalyzed highly regio- and enantioselective reductive coupling of alkynes and aldehydes has been developed under visible light photoredox dual catalysis. A variety of enantioenriched allylic alcohols have been obtained by using unsymmetrical internal alkynes and commercially available catalyst, chiral ligand, and reagents. It is noteworthy that this approach has considerable advantages, such
在可见光光氧化还原双催化下开发了一种共催化的炔烃和醛的高度区域选择性和对映选择性还原偶联。通过使用不对称内部炔烃和市售催化剂、手性配体和试剂,已经获得了多种对映体富集的烯丙醇。值得注意的是,这种方法具有相当大的优势,例如出色的区域-(> 40 个示例> 95:5)、立体-(高达> 95:5 E / Z)和对映选择性(92-99% ee,> 35个例子)控制,反应条件温和,底物范围广,官能团相容性好,使其对映选择性炔-醛还原偶联反应有了很大的改进。
Axial Coordination of NHC Ligands on Dirhodium(II) Complexes: Generation of a New Family of Catalysts
作者:Alexandre F. Trindade、Pedro M. P. Gois、Luís F. Veiros、Vânia André、M. Teresa Duarte、Carlos A. M. Afonso、Stephen Caddick、F. Geoffrey N. Cloke
DOI:10.1021/jo800087n
日期:2008.6.1
An efficient new methodology for the arylation of aldehydes is disclosed which uses dirhodium(II) catalysts and N-heterocyclic carbene (NHC) ligands. Complexes of Rh2(OAc)4 with one and two NHCs attached on the axial positions were successfully isolated, fully characterized, and used as catalysts in the reaction. The saturated monocomplex ((NHC 5)Rh2(OAc)4) 31 was shown to be the most active catalyst
Aqueous Reaction of Alcohols, Organohalides, and Odorless Sodium Thiosulfate under Transition-Metal-Free Conditions: Synthesis of Unsymmetrical Aryl Sulfides via Dual C–S Bond Formation
作者:Bei-Bei Liu、Xue-Qiang Chu、Huan Liu、Ling Yin、Shun-Yi Wang、Shun-Jun Ji
DOI:10.1021/acs.joc.7b01653
日期:2017.10.6
A transition-metal-free process for the synthesis of unsymmetrical aryl sulfides via dual C–S bond formation by a one-pot three-component reaction of alcohols, organohalides, and odorless sodium thiosulfate in water has been developed. In addition, the aryl sulfides could also be prepared by the reaction of the corresponding alcohols and Bunte salts under the identical conditions. This protocol provides