nickel and chiralamine cooperative catalysis to enable a highlyenantioselectiveallylic alkylation reaction between α-branched aldehydes and a wide scope of allyl esters, allowing the all-carbon quaternary stereocenter to be accessed with excellent enantioselectivity (up to 98% ee) and structural diversity. The general synthetic applicability has been showcased by the enantioselective synthesis of
全碳四元立体中心构成了天然产物和生物活性化合物的重要组成部分。在这里,我们公开了一种镍和手性胺协同催化,使 α-支化醛和各种烯丙基酯之间发生高度对映选择性的烯丙基烷基化反应,从而以优异的对映选择性(高达 98% ee ) 和结构多样性。关键手性构件的对映选择性合成以获取 (+)-依他佐辛、(-)-aphanorphine 和其他两种生物活性化合物,展示了一般合成适用性。
Ruthenium(II)-Catalyzed Cyclization of Aromatic Acids with Allylic Acetates via Redox-Free Two-Fold Aromatic/Allylic C–H Activations: Combined Experimental and DFT Studies
A Ru(II)-catalyzed, redox-free, two-fold aromatic/allylic C–H bond activation of aromatic acids with allylic acetates to give (Z)-3-ylidenephthalides is described. In the reaction, H2 was formed as a side product. The detailed mechanistic investigation and DFT studies including the transition-state analysis support the postulate that the C–H allylation takes place at the ortho position of aromatic
Enantioselective Allylic Alkylation with 4-Alkyl-1,4-dihydro-pyridines Enabled by Photoredox/Palladium Cocatalysis
作者:Hong-Hao Zhang、Jia-Jia Zhao、Shouyun Yu
DOI:10.1021/jacs.8b10766
日期:2018.12.12
alkylation has been achieved enabled by the merger of photoredox and palladiumcatalysis. In this dual catalytic process, alkyl radicals generated from 4-alkyl-1,4-dihydropyridines act as the coupling partners of the π-allyl palladium complexes. The generality of this method has been illustrated through the reaction of a variety of allylesters with 4-alkyl-1,4-dihydropyridines. This mechanistically novel
Nickel/Photo-Cocatalyzed C(sp<sup>2</sup>)–H Allylation of Aldehydes and Formamides
作者:Pei Fan、Rui Wang、Chuan Wang
DOI:10.1021/acs.orglett.1c02938
日期:2021.10.1
nickel/photo-cocatalyzed C(sp2)–H allylation of aldehydes and formamides wherein both allyl acetates and allylalcohols can be used as the allylating agents. In this reaction, radical-type umpolung of the formyl moiety is enabled by tetrabutylammonium decatungstate as a hydrogen-atom-transfer photocatalyst, whereas nickel serves to cleave the C–O bond of allyl acetates or allylalcohols. The synergistic effect
Enantioselective α-Allylation of Anilines Enabled by a Combined Palladium and Photoredox Catalytic System
作者:Hong-Hao Zhang、Jia-Jia Zhao、Shouyun Yu
DOI:10.1021/acscatal.0c00871
日期:2020.4.17
branch-regioselective α-allylation of N-methyl anilines under dual palladium/photoredoxcatalysis is described. Readily available N-methyl anilines are used as formal “hard” alkyl nucleophiles without preactivation. Acetic acid is the only side product, which leads to a high atom economy of this reaction. This protocol shows good functional group tolerance and broad scope. A range of chiral homoallylic amines were