Radical Desulfur‐Fragmentation and Reconstruction of Enol Triflates: Facile Access to α‐Trifluoromethyl Ketones
作者:Xiaolong Su、Honggui Huang、Yaofeng Yuan、Yi Li
DOI:10.1002/anie.201608507
日期:2017.1.24
efficient oxidative radical desulfur‐fragmentation and reconstruction of enoltriflates for the synthesis of α‐CF3 ketones. Preliminary mechanistic studies disclosed that oxidative fragmentation to release a CF3 radical from the triflyl group of enoltriflate and subsequent addition of the CF3 radical to another enoltriflate form the desired α‐CF3 ketones. This method provides a new approach to α‐CF3
Visible light induced Trifluoromethyl Migration: Easy Access to α-Trifluoromethylated Ketones from Enol Triflates
作者:Shuyang Liu、Jiyang Jie、Jipan Yu、Xiaobo Yang
DOI:10.1002/adsc.201701051
日期:2018.1.17
Herein, we reported a novel method to synthesize α-trifluoromethylated ketones from enol triflates. Involving a cascade sulfurdioxide extrusion and a CF3 (trifluoromethyl) radical addition process, this reaction proceeds at room temperature and is driven by visible light irradiation. This protocol bears good functional group compatibility, which can generate the desired products in good to excellent
Enantioselective Construction of Quaternary Stereogenic Centers by the Addition of an Acyl Anion Equivalent to 1,3-Dienes
作者:Nathan J. Adamson、Sangjune Park、Pengfei Zhou、Andrew L. Nguyen、Steven J. Malcolmson
DOI:10.1021/acs.orglett.0c00412
日期:2020.3.6
We report the enantioselective formation of quaternary stereogenic centers by the intermolecular addition of malononitrile, an acyl anion equivalent, and related pronucleophiles to several 1,3-disubstituted acyclic 1,3-dienes in the presence of a Pd-PHOX catalyst. Products are obtained in up to 88% yield and 99:1 er and in most cases are formed as a single regioisomer. The products' malononitrile unit
intermediate as an electrophile, which is corroborated by DFT calculations, deuterium-labeling and other control experiments. The use of an inert weakly coordinating anion is a decisive factor in this bimolecular vinylation process.
Photoredox- or Metal-Catalyzed in Situ SO<sub>2</sub>-Capture Reactions: Synthesis of β-Ketosulfones and Allylsulfones
作者:Min Zheng、Guigen Li、Hongjian Lu
DOI:10.1021/acs.orglett.9b00201
日期:2019.2.15
as radical acceptors and SO2 sources to provide various β-ketosulfones and allylsulfones, known to be significant building blocks. Without the use of any additives including external SO2 gas, the reaction was performed under mild photoredox- or metal-catalytic conditions while tolerating various functional groups.