Iridium-Catalyzed Direct C–H Sulfamidation of Aryl Nitrones with Sulfonyl Azides at Room Temperature
作者:Chao Pi、Xiuling Cui、Yangjie Wu
DOI:10.1021/acs.joc.5b01377
日期:2015.8.7
Ir(III)-catalyzed direct C–H sulfamidation of aryl nitrones has been developed to synthesize various sulfamidated nitrones in moderate to excellent yields with excellent regioselectivity and broad functional group tolerance. This transformation could proceed smoothly at roomtemperature with low catalyst loading in the absence of external oxidants, acids, or bases. Molecular nitrogen was released as
Borrowing and Returning Oxygen Atom in Trifluoroacetic Anhydride Transfer to Nitrones: A Versatile Route for the Synthesis of <i>N</i>
-Trifluoroacetyl Amides
作者:Junwen Wang、Zhiqiang Weng
DOI:10.1002/ejoc.201801662
日期:2019.2.14
A variety of N‐trifluoroacetyl amides are obtained from trifluoroaceticanhydride transfers to nitrones through borrowing and returning oxygen atom. This transformation proceeds smoothly under mild conditions via electrophilic trifluoroacetylation, followed by nucleophilicaddition and elimination, and intramolecular substitution. Furthermore, the method also provides efficient access to N‐difluoroacetyl
2,2,2-Trifluoroacetaldehyde <i>O</i>-(Aryl)oxime: A Precursor of Trifluoroacetonitrile
作者:Bo Lin、Yunfei Yao、Yangjie Huang、Zhiqiang Weng
DOI:10.1021/acs.orglett.2c00637
日期:2022.3.18
The preparation of 2,2,2-trifluoroacetaldehyde O-(aryl)oxime, a previously inaccessible precursor of trifluoroacetonitrile, via reaction of hydroxylamine and trifluoroacetaldehyde hydrate is reported. This precursor released CF3CN in quantitative yield under mildly basic conditions. The precursor was successfully used in the synthesis of trifluoromethylated oxadiazoles. The facile, cost-effective,
Nitrone Directing Groups in Rhodium(III)-Catalyzed C−H Activation of Arenes: 1,3-Dipoles versus Traceless Directing Groups
作者:Fang Xie、Songjie Yu、Zisong Qi、Xingwei Li
DOI:10.1002/anie.201609658
日期:2016.12.5
Functionalizable directing groups (DGs) are highly desirable in C−H activation chemistry. The nitrone DGs are explored in rhodium(III)‐catalyzedC−H activation of arenes and couplings with cyclopropenones. N‐tert‐butyl nitrones bearing a small ortho substituent coupled to afford 1‐naphthols, where the nitrone acts as a traceless DG. In contrast, coupling of N‐tert‐butyl nitrones bearing a bulky ortho