574-61-8Relevant articles and documents
Synthesis of 1: H -indazoles by an electrochemical radical Csp2-H/N-H cyclization of arylhydrazones
Alhumade, Hesham,Lei, Aiwen,Li, Dongting,Wan, Hao,Xia, Huadan,Yang, Liwen,Yi, Hong
, p. 665 - 668 (2022/01/22)
The development of efficient and sustainable C-N bond-forming reactions to N-heterocyclic frameworks has been a long-standing interest in organic synthesis. In this work, we develop an electrochemical radical Csp2-H/N-H cyclization of arylhydrazones to 1H-indazoles. The electrochemical anodic oxidation approach was adopted to synthesize a variety of 1H-indazole derivatives in moderate to good yields. HFIP was not only employed as a solvent or the proton donor, but also can promote the formation of N free radicals. This synthetic methodology is operationally simple, and less expensive electrodes would be suitable for this chemistry. This journal is
Transition-Metal-Free Coupling of 1,3-Dipoles and Boronic Acids as a Sustainable Approach to C?C Bond Formation
Livingstone, Keith,Bertrand, Sophie,Kennedy, Alan R.,Jamieson, Craig
, p. 10591 - 10597 (2020/07/25)
The need for alternative, complementary approaches to enable C?C bond formation within organic chemistry is an on-going challenge in the area. Of particular relevance are transformations that proceed in the absence of transition-metal reagents. In the current study, we report a comprehensive investigation of the coupling of nitrile imines and aryl boronic acids as an approach towards sustainable C?C bond formation. In situ generation of the highly reactive 1,3-dipole facilitates a Petasis–Mannich-type coupling via a nucleophilic boronate complex. The introduction of hydrazonyl chlorides as a complementary nitrile imine source to the 2,5-tetrazoles previously reported by our laboratory further broadens the scope of the approach. Additionally, we exemplify for the first time the extension of this protocol into another 1,3-dipole, through the synthesis of aryl ketone oximes from aryl boronic acids and nitrile N-oxides.
Metal-free C-C bond formation: Via coupling of nitrile aimines and boronic acids
Livingstone, Keith,Bertrand, Sophie,Mowat, Jenna,Jamieson, Craig
, p. 10412 - 10416 (2019/11/20)
The challenges of developing sustainable methods of carbon-carbon bond formation remains a topic of considerable importance in synthetic chemistry. Capitalizing on the highly reactive nature of the nitrile imine 1,3-dipole, we have developed a novel metal-free coupling of this species with aryl boronic acids. Photochemical generation of a nitrile imine intermediate and trapping with a palette of boronic acids enabled rapid and facile access to a broad library of more than 25 hydrazone derivatives in up to 92% yield, forming a carbon-carbon bond in a metal free fashion. This represents the first reported example of direct reaction between boronic acids and a 1,3-dipole.