Readily Removable Directing Group Assisted Chemo- and Regioselective C(sp(3))-H Activation by Palladium Catalysis
Yun-Fei Zhang1, Hong-Wei Zhao2, Hui Wang1
1Beijing National Laboratory of Molecular Sciences (BNLMS) and Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering and Green Chemistry Center, Peking University, Beijing, 100871 (China).
Abstract:
Currently used directing groups for selective aliphatic β-functionalization of carbonyl compounds show excellent reactivity and selectivity with an amide as a linker. Described herein is 2-piconimide, used for the first time with commercially available 2-picolinamide/2-picolic acid as precursors, to direct C-H arylation/alkenylation by palladium catalysis. The directing group is essential for promoting the sequnetial primary and secondary C(sp(3))-H arylation with different aryl iodides in one substrate. The directing group was easily removed under simple reaction conditions at room temperature.
More Related Videos
06:26Achieving Moderate Pressures in Sealed Vessels Using Dry Ice As a Solid CO2 Source
Published on: August 17, 2018
11:44Mizoroki-Heck Cross-coupling Reactions Catalyzed by Dichloro{bis[1,1',1''-phosphinetriyltripiperidine]}palladium Under Mild Reaction Conditions
Published on: March 20, 2014
Related Concept Videos
ortho–para-Directing Activators: –CH3, –OH, –⁠NH2, –OCH3
Radical Anti-Markovnikov Addition to Alkenes: Overview
Regioselectivity and Stereochemistry of Hydroboration
Hydroboration proceeds in a concerted fashion with the attack of borane on the π bond, giving a cyclic four-centered transition state. The –BH2 group is bonded to the less substituted carbon and –H to the more substituted carbon. The concerted nature requires the simultaneous addition of –H and –BH2 across the same face of the alkene giving syn stereochemistry.
Regioselectivity of Electrophilic Additions-Peroxide Effect
Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
Regioselectivity of Electrophilic Additions to Alkenes: Markovnikov's Rule
The hydrohalogenation of an unsymmetrical alkene can yield two haloalkane products, depending on which vinylic carbon takes up the halogen. However, one product usually predominates, where hydrogen adds to the vinylic carbon bearing the...
