Ligand‐Controlled Copper‐Catalyzed Highly Regioselective Difluoromethylation of Allylic Chlorides/Bromides and Propargyl Bromides. Issue 1 (27th November 2017)

• Record Type: Journal Article
• Authors: Gu, Yang; Lu, Changhui; Gu, Yucheng; Shen, Qilong
• Is Part Of: Chinese journal of chemistry. Volume 36:Issue 1(2018)
• Page Start: 55
• Page End: 58
• Publication Date: 2017-11-27
• Subjects: fluorine -- difluoromethyl -- copper -- asymmetric -- allylic substitution; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/cjoc.201700594
• Languages: English
• ISSNs: 1001-604X

Abstract

Abstract : Highly regiodivergent copper‐catalyzed allylic/propargylic difluoromethylation reactions by employing different ligands are described. When 5, 6‐dimethyl‐1, 10‐phenanthroline was used as the ligand, exclusively α‐difluoromethylated products were obtained, while γ‐selective difluoromethylated products were generated when N ‐heterocyclic carbene‐SIPr was used as the ligand. Likewise, high α‐ vs. γ‐selectivities were achieved in the presence of similar copper catalysts for the reactions of propargyl bromides. Moreover, a copper‐catalyzed asymmetric allylic difluoromethylation reaction with moderate to good enantioselectivity by the use of chiral ligands was developed. Abstract : Highly regiodivergent copper‐catalyzed allylic/propargylic difluoromethylation reactions by employing different ligands are described. When 5, 6‐dimethyl‐1, 10‐phenanthroline was used as the ligand, exclusively α‐difluoromethylated products were obtained, while γ‐selective difluoromethylated products were generated when N ‐heterocyclic carbene‐SIPr was used as the ligand. Likewise, high α‐ vs. γ‐selectivities were achieved in the presence of similar copper catalysts for the reactions of propargyl bromides.