2-aryl-3-arylazoacrylonitriles are synthesized while attempting the intramolecular N-arylation of 5-aminopyrazoles, using the hypervalent iodine reagent. The synthesis involves phenyl iodine diacetate-assisted ringopening of 5-aminopyrazoles at room temperature. A plausible mechanism for the formation of azoalkenes is proposed.
Synthesis of Vinyl Cyclopropanes via Anion Relay Cyclization
作者:Kevin M. Allegre、Nathan Brennan、Jon A. Tunge
DOI:10.1021/acs.orglett.8b01566
日期:2018.7.20
A method where an allylalcohol is formed from a Tsuji–Trost allylation between a vinyl epoxide and an acyl containing nucleophile is described. Subsequently, a retro-Claisen condensation is utilized as a means of through-space anion relay. The anion relay results in the formation of a reactive carbanion and simultaneously activates an allylic alcohol toward intramolecular Tsuji–Trost cyclopropanation
Rhodium‐Catalyzed Asymmetric Hydrogenation of Tetrasubstituted α,β‐Unsaturated Amides: Efficient Access to Chiral β‐Amino Amides†
作者:Bing Jiao、Fangyuan Wang、Hui Lv
DOI:10.1002/cjoc.202400344
日期:2024.11
The first asymmetrichydrogenation of acyclic tetrasubstituted α,β-unsaturated amides has been achieved by usingRh/DuanPhos complex as a catalyst, delivering chiral β-amino amides with two contiguous chiral centers in excellent yields and high enantioselectivities (up to 99% yield, 96% ee), which provides efficient and concise access to valuable β-amino amide derivatives. The gram-scale reaction and
We present a new strategy for the dearomatized hydroxylation of 5-aminopyrazoles using a hypervalent iodine reagent at room temperature. This method produces a series of 4-hydroxy-5-iminopyrazolines with good to excellent yields within 2 hours. Additionally, we demonstrate a domino reaction for the synthesis of 4-hydroxy-pyrazolones. Mechanistic studies indicate that the dearomatization proceeds through