Denitrogenative Hydrotrifluoromethylation of Benzaldehyde Hydrazones: Synthesis of (2,2,2‐Trifluoroethyl)arenes
作者:Zhensheng Zhao、Kevin C. Y. Ma、Claude Y. Legault、Graham K. Murphy
DOI:10.1002/chem.201902818
日期:——
hydrazones of arylaldehydes with Togni's CF3 -benziodoxolone reagent, in the presence of potassium hydroxide and cesium fluoride, induces a denitrogenative hydrotrifluoromethylation event to produce (2,2,2-trifluoroethyl)arenes. This novel reaction was tolerant to many electronically-diverse functional groups and substitution patterns, as well as naphthyl- and heteroaryl-derived substrates. Advantages of this
Umpolung of Carbonyl Groups as Alkyl Organometallic Reagent Surrogates for Palladium-Catalyzed Allylic Alkylation
作者:Dianhu Zhu、Leiyang Lv、Chen-Chen Li、Sosthene Ung、Jian Gao、Chao-Jun Li
DOI:10.1002/anie.201809112
日期:2018.12.10
carbon nucleophiles is difficult and remains a major challenge. Reported here is a highly chemo‐ and regioselective direct palladium‐catalyzed C‐allylation of hydrazones, generated from carbonyls, as a source of umpolung unstabilized alkyl carbanions and surrogates of alkyl organometallicreagents. Contrary to classical allylation techniques, this umpolung reaction utilizes hydrazones prepared not
Nickel-Catalyzed Cross-Coupling of Umpolung Carbonyls and Alkyl Halides
作者:Dianhu Zhu、Leiyang Lv、Zihang Qiu、Chao-Jun Li
DOI:10.1021/acs.joc.9b00649
日期:2019.5.17
nickel-catalyzed cross-coupling of Umpolung carbonyls and alkylhalides was developed. Complementary to classical alkylation techniques, this reaction utilizes Umpolung carbonyls as the environmentally benign alkyl nucleophiles, providing an efficient and selective catalytic alternative to the traditional use of highly reactive alkylorganometallic reagents.
Switch in Selectivity for Formal Hydroalkylation of 1,3‐Dienes and Enynes with Simple Hydrazones
作者:Leiyang Lv、Lin Yu、Zihang Qiu、Chao‐Jun Li
DOI:10.1002/anie.201915875
日期:2020.4.16
anti-Markovnikov addition is obtained by changing to a ruthenium catalyst, thus providing direct and efficient access to homoallylic products exclusively. Isotopic substitution experiments indicate that no reversible hydro-metallation across the metal-π-allyl system occurred under ruthenium catalysis. Moreover, this protocol is applicable to the regiospecific hydroalkylation of the distal C=C bond of 1,3-enynes