Related Experiment Video
Updated: Sep 19, 2025
Synthesis of Hypervalent Iodonium Alkynyl Triflates for the Application of Generating Cyanocarbenes
Published on: September 8, 2013
Photocatalyzed Oxycarboranylation of Alkenes with 1-Iodo-o-carboranes through a Halogen-Atom Transfer Strategy
Li-Xin Li1,2, Zhuo Chen1, Zi-Teng Yang1
1Academy of Chinese Medical Science, Henan University of Chinese Medicine, Zhengzhou 450046, China.
Abstract:
Carboranes are of growing importance to pharmaceutical chemistry as the key units of boron neutron capture therapy (BNCT) reagents and the three-dimensional analogue of benzene. Light-induced functionalization of carboranes is a powerful tool for constructing carborane-containing compounds. However, in comparison to the various methods forming boron-centered carboranyl radicals, those for carbon-centered carboranyl radicals are limited to the direct absorption of light energy through carborane, which is a challenge for substrate accessibility and diversity transformations. Here, we reported a method for the generation of electrophilic carbon-centered carboranyl radicals by a polarity-matched halogen-atom transfer (XAT) process and their transformation with alkenes to afford alcohols. The practicality of this protocol was emphasized by the late-stage functionalization of drugs and natural products. Mechanistic studies elucidated that fast and efficient generation of carbon-centered carboranyl radicals through nucleophilic radical abstractors is crucial.
More Related Videos
09:54Chemoselective Preparation of 1-Iodoalkynes, 1,2-Diiodoalkenes, and 1,1,2-Triiodoalkenes Based on the Oxidative Iodination of Terminal Alkynes
Published on: September 12, 2018
08:56Synthesis of a Borylated Ibuprofen Derivative Through Suzuki Cross-Coupling and Alkene Boracarboxylation Reactions
Published on: November 30, 2022
Related Concept Videos
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.
01:21Acid-Catalyzed α-Halogenation of Aldehydes and Ketones
In the first step of the mechanism, the acid protonates the carbonyl oxygen resulting in a resonance-stabilized cation, which subsequently loses an α-hydrogen to form an enol tautomer. The C=C bond in an enol is highly nucleophilic because of the electron-donating nature of the –OH group. Consequently, the double bond attacks an electrophilic halogen to form a...
02:46Halogenation of Alkenes
Consider the bromination of cyclopentene. Molecular bromine is polarized in the proximity of the π electrons of cyclopentene. An electrophilic bromine atom adds across the double bond, forming a cyclic bromonium ion intermediate.
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...
00:51Base-Promoted α-Halogenation of Aldehydes and Ketones