Related Experiment Video
Updated: Jan 9, 2026
Efficient Synthesis of All-Carbon Quaternary Centers via the Conjugate Addition of Functionalized Monoorganozinc Bromides
Published on: May 26, 2019
Condition-Controlled Regio- and Chemoselective Allylic Alkylation of 2-Substituted Quinolin-4-ones with MBH
Dongyi Zhang1, Chunling Lu1, Zhuoqi Zhang1
1The Center for Combinatorial Chemistry and Drug Discovery of Jilin University, The School of Pharmaceutical Sciences, Jilin University, 1266 Fujin Road, Changchun 130021, P. R. China.
Abstract:
Condition-switchable, regiodivergent O-, N-, and C-allylation of quinolin-4-ones with Morita-Baylis-Hillman (MBH) carbonates is disclosed. Systematic modulation of the Lewis/Brønsted base catalyst and solvent enables programmable site-selectivity: γ-O-allylation proceeds exclusively under condition A (10 mol % DABCO, CH2Cl2, 25 °C), whereas α-O-allylation is favored under condition B (10 mol % K2CO3, DMF, 80 °C); subsequently, N1- and C3-allylations are achieved under condition C (20 mol % DMAP, t-BuOH, 80 °C) and conditions D (10 mol % DABCO, DCE, 100 °C), respectively. The protocol features broad substrate scope, high yields (up to 99%), and excellent selectivity. Mechanistic studies support O-to-N and O-to-C rearrangement pathways for N1- and C3-products, respectively. This operationally simple method provides a practical platform for late-stage diversification of medicinally relevant quinolin-4-ones.
Related Concept Videos
02:17Regioselectivity 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...
02:36Regioselectivity 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.
01:25Radical Anti-Markovnikov Addition to Alkenes: Overview
03:08Hydroboration-Oxidation of Alkenes
02:47Alkynes to Aldehydes and Ketones: Hydroboration-Oxidation
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.
01:11Nucleophilic Aromatic Substitution: Elimination–Addition