Cobalt(II)‐Catalyzed [4+2] Annulation of Picolinamides with Alkynes via C−H Bond Activation. Issue 25 (17th April 2020)

• Record Type: Journal Article
• Authors: Yao, Yongqi; Lin, Qifu; Yang, Wen; Yang, Weitao; Gu, Fenglong; Guo, Wei; Yang, Dingqiao
• Is Part Of: Chemistry. Volume 26:Issue 25(2020)
• Page Start: 5607
• Page End: 5610
• Publication Date: 2020-04-17
• Subjects: [4+2] annulation -- alkynes -- C−H bond activation -- cobalt(II) catalyst -- co-oxidant free; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.202000411
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: A cobalt(II)‐catalyzed [4+2] annulation of picolinamides with alkynes via C−H bond activation has been developed. The operationally simple annulation reaction allows for the synthesis of acyl‐substituted 1 H ‐benzoquinoline bearing multiple aromatic rings (up to 96 % yield) without co‐oxidant or other oxidation factors under mild conditions. Several control experiments were carried out. This practical [4+2] annulation provides an efficient route to access highly functionalized compounds. Abstract : Free from any oxidation factor : A co‐oxidant free cobalt(II)‐catalyzed picolinamide‐directed annulation of alkyne via C(sp 2 )−H bond activation was developed. Under the optimized reaction condition, the reaction system shows a wide scope of alkynes and obtains the novel annulation acyl‐substituted 1 H ‐benzoquinoline in good to excellent yields (up to 96 %).