Nickel-Catalyzed Enantioselective α-Alkenylation of <i>N</i>-Sulfonyl Amines: Modular Access to Chiral α-Branched Amines
作者:Lun Li、Yu-Cheng Liu、Hang Shi
DOI:10.1021/jacs.1c00622
日期:2021.3.24
α-branched amines are common structural motifs in functional materials, pharmaceuticals, and chiral catalysts. Therefore, developing efficient methods for preparing compounds with these privileged scaffolds is an important endeavor in synthetic chemistry. Herein, we describe an atom-economical, modular method for a nickel-catalyzed enantioselective α-alkenylation of readily available linear N-sulfonyl amines
Syngas‐Free Highly Regioselective Rhodium‐Catalyzed Transfer Hydroformylation of Alkynes to α,β‐Unsaturated Aldehydes
作者:Guangying Tan、Yimin Wu、Yang Shi、Jingsong You
DOI:10.1002/anie.201902553
日期:2019.5.27
fundamental and important reaction in both academic research and industry. Conventional methods focus on the conversion of alkynes, CO, and H2 into α,β‐unsaturated aldehydes, but they often suffer from problems associated with operation, regioselectivity, and chemoselectivity. Herein, we disclose an operationally simple, mild, and syngas‐free rhodium‐catalyzed reaction for the hydroformylation of alkynes
to selectively afford the corresponding 8-vinyl-1-naphthol derivatives. N-(1-Naphthyl)benzenesulfonamides can similarly react with the alkynes. The reaction of salicylaldehyde with the alkynes using the catalyst system gives 2-hydroxyphenyl vinyl ketones via cleavage of the aldehyde C–H bond.
A copper-catalyzedoxidative cleavage reaction of alkynes using NFSI and TBHP was described. Various terminal and internal alkyne substrates were employed to render quick access to aryl ketone products in moderate to good yields. NFSI not only functioned as N-centered radical precursors but also engaged in the aryl group migration. Mechanistic studies also suggested the important role of water in the
A step‐ and redox‐economic route toward aminoallenes from simplealkynes and N‐fluorobenzenesulfonimide (NFSI) was established viaselenium‐π‐acid catalysis. This unprecedented method significantly streamlines the assembly of heterosubstituted 1,3‐propadiene motifs and is characterized by a broad functional group tolerance.