Related Experiment Video
Updated: Mar 23, 2026

A Two-Step Protocol for Umpolung Functionalization of Ketones Via Enolonium Species
Published on: August 16, 2018
Enantioselective bromocyclization of 2-geranylphenols induced by chiral phosphite-urea bifunctional catalysts
Yasuhiro Sawamura1, Yoshihiro Ogura, Hidefumi Nakatsuji
1Graduate School of Engineering, Nagoya University, B2-3(611), Furo-cho, Chikusa, Nagoya 464-8603, Japan. ishihara@cc.nagoya-u.ac.jp.
Abstract:
Chiral phosphite-urea bifunctional catalysts have been developed for the enantioselective bromocyclization of 2-geranylphenols with N-bromophthalimide (NBP) for the first time. The chiral triaryl phosphite moiety activates NBP to generate a bromophosphonium ion. On the other hand, the urea moiety interacts with a hydroxyl group of the substrate through hydrogen bonding interactions. Enantioselectivity is effectively induced through two-point attractive interactions between the catalyst and the substrate.
Related Concept Videos
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
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...
Regioselectivity and Stereochemistry of Acid-Catalyzed Hydration
Diels–Alder Reaction Forming Bridged Bicyclic Products: Stereochemistry
α-Bromination of Carboxylic Acids: Hell–Volhard–Zelinski Reaction

![[DPEPhosbcpCu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F59739.jpg&w=3840&q=50)