Studies on the Chemistry and Reactivity of α-Substituted Ketones in Isonitrile-Based Multicomponent Reactions
作者:Lijun Fan、Ashley M. Adams、Jason G. Polisar、Bruce Ganem
DOI:10.1021/jo8019708
日期:2008.12.19
Using the Passerini and Ugi reactions as representative tests, the utility of several alpha-substituted ketones R-CO-CH(2)-X (X = sulfonyloxy, acyloxy, azido, halo, hydroxy, and sulfonyl) in isonitrile-based multicomponent reactions was explored. In a relative rate study (R = PhCH(2)CH(2)), each of the alpha-substituted ketones underwent Passerinicondensation more rapidly than the parent ketone. Short
Catalyst-Free <i>gem</i>-Difunctionalization of Fluoroalkyl-Substituted Diazo Compound with Diselenide or Disulfide and NFSI
作者:Jiuling Li、Chaoqun Ma、Dong Xing、Wenhao Hu
DOI:10.1021/acs.orglett.9b00382
日期:2019.4.5
The gem-difunctionalization of fluoroalkyl-substituted diazo compounds by utilizing diselenides or disulfides and NFSI under catalyst-free and mild conditions is reported. A series of gem-aminoselenolation and gem-aminosulfonylation products bearing fluoroalkyl substituents were obtained in high to excellent yields. Different types of conjugated diazo compounds are also applicable to this transformation
Rh2(OAc)4-assisted decompositions of diazoacetylcycloalkanes are shown to yield cycloalkylacetic acids (Wolff rearrangement), unexpected cycloalkylcarboxylic acids and bicyclic ketones (intramolecular CH bond insertion). Rh2(OCOCF3)4-promoted reactions, on the other hand, have furnished bicyclic ketones and ketene dimers.
A Conjugate Addition Approach to Diazo‐Containing Scaffolds with β Quaternary Centers
作者:Jian Fang、Evan M. Howard、Matthias Brewer
DOI:10.1002/anie.202004557
日期:2020.7.27
salts. The electrophile, a little studied α‐diazonium‐α,β‐unsaturated carbonyl compound, is formed at low temperature under mild conditions by treating β‐hydroxy‐α‐diazo carbonyls with Sc(OTf)3. Conjugate addition occurs selectively at the 3‐position of indole to give α‐diazo‐β‐indole carbonyls, and enoxy silanes react to give 2‐diazo‐1,4‐dicarbonyl products. These reactions result in the formation