Related Experiment Video
Updated: May 27, 2025
![Solid-phase Synthesis of [4.4] Spirocyclic Oximes](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F58508.jpg&w=3840&q=50)
Solid-phase Synthesis of [4.4] Spirocyclic Oximes
Published on: February 6, 2019
Hydride Transfer-Enabled Dearomative Spirocyclization of Isoxazoles with O-Alkyl ortho-Oxybenzaldehydes
Lianyi Cao1, Shihai Yan2, Fangzhi Hu2
1Department of Chemistry, Xihua University, Chengdu 610039, P. R. China.
Abstract:
The TfOH-catalyzed dearomative [5 + 1] annulations were developed for the construction of chromane-fused spiroisoxazolines from readily available 5-amino-isoxazoles and O-alkyl ortho-oxybenzaldehydes. The "two-birds-with-one-stone" strategy featuring dearomatization of 5-amino-isoxazoles and α-C(sp3)-H bond functionalization of oxygen was disclosed via a cascade condensation/[1,5]-hydride transfer/dearomative spirocyclization process. In addition, the unprecedented direct dearomative spirocyclization of isoxazoles was achieved, which introduced a new family member of dearomative spirocyclization for dearomatization chemistry.
More Related Videos
12:27Synthesis of Hypervalent Iodonium Alkynyl Triflates for the Application of Generating Cyanocarbenes
Published on: September 8, 2013
10:17Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of α-Imino γ-Lactones and Alkylidene Pyrazolones
Published on: February 7, 2019
Related Concept Videos
02:44Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide
03:00Preparation of Epoxides
Epoxides result from alkene oxidation, which can be achieved by a) air, b) peroxy acids, c) hypochlorous acids, and d) halohydrin cyclization.
Epoxidation with Peroxy Acids
Epoxidation of alkenes via oxidation with peroxy acids involves the conversion of a carbon–carbon double bond to an epoxide using the oxidizing agent meta-chloroperoxybenzoic acid, commonly known as MCPBA. Since the O–O bond of peroxy acids is very weak, the addition of electrophilic oxygen of...
02:04Oxidation of Alkenes: Anti Dihydroxylation with Peroxy Acids
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.
03:08Hydroboration-Oxidation of Alkenes
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...