Aldehydes as alkyl carbanion equivalents for additions to carbonyl compounds
作者:Haining Wang、Xi-Jie Dai、Chao-Jun Li
DOI:10.1038/nchem.2677
日期:2017.4
ruthenium catalyst and diphosphine ligand under mild conditions, delivering synthetically valuable secondary and tertiary alcohols in up to 98% yield. The unique chemoselectivity exhibited by carbonyl-derived carbanion equivalents is demonstrated by their tolerance to protic reaction media and good functional group compatibility. Enantioenriched tertiary alcohols can also be accessed with the aid of chiral
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
hydroalkylation of dienes with stabilized carbon nucleophiles has been made, hydroalkylation of dienes with unstabilized carbon nucleophiles has remained a challenge. In this article, we report a protocol for nickel-catalyzed hydroalkylation of dienes with hydrazones, which serve as equivalents of alkyl carbon nucleophiles. In addition, we developed a protocol for hydroalkenylation of dienes with α,β-unsaturated
Metal-Free Construction of the C(sp<sup>3</sup>)–CF<sub>3</sub> Bond: Trifluoromethylation of Hydrazones with Togni’s Reagent under Mild Conditions
作者:Huiying Zeng、Zhen Luo、Xinlong Han、Chao-Jun Li
DOI:10.1021/acs.orglett.9b02072
日期:2019.8.2
A metal-free trifluoromethylation of hydrazones with Togni’s reagent under mild conditions was developed. Various functional groups including ester, methoxy, dimethoxy, nitro, halogen, and heterocyclic compounds were tolerated. This simple and green strategy provides a practical tool to construct C(sp3)–CF3 bonds.
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