In organic chemistry, a directing group (DG) is a substituent on a molecule or ion that facilitates reactions by interacting with a reagent. The term is usually applied to C–H activation of hydrocarbons, where it is defined as a "coordinating moiety (an 'internal ligand'), which directs a metal catalyst into the proximity of a certain C–H bond."[1] In a well known example, the ketone group (C=O) in acetophenone is the DG in the Murai reaction.[1]
The Murai reaction is related to directed ortho metalation, a reaction is typically applied to the lithiation of substituted aromatic rings.[2]
A wide variety of functional groups can serve as directing groups.[3]
- ^ a b Sambiagio, C.; D. Schönbauer; R. Blieck; T. Dao-Huy; G. Pototschnig; P. Schaaf; T. Wiesinger; M. F. Zia; J. Wencel-Delord; T. Besset; B. U. W. Maes; M. Schnürch (2018). "A Comprehensive Overview of Directing Groups Applied in Metal-Catalysed C–H functionalisation chemistry". Chem. Soc. Rev. 47 (17): 6603–6743. doi:10.1039/C8CS00201K. PMC 6113863. PMID 30033454.
- ^ Snieckus, Victor (1990). "Directed ortho metalation. Tertiary amide and O-carbamate directors in synthetic strategies for polysubstituted aromatics" Chem. Rev.; 90 (6): 879–933.
- ^ He, Jian; Wasa, Masayuki; Chan, Kelvin S. L.; Shao, Qian; Yu, Jin-Quan (2017). "Palladium-Catalyzed Transformations of Alkyl C–H Bonds". Chemical Reviews. 117 (13): 8754–8786. doi:10.1021/acs.chemrev.6b00622. PMC 5516964. PMID 28697604.