Preparation of Chiral Allenes through Pd-Catalyzed Intermolecular Hydroamination of Conjugated Enynes: Enantioselective Synthesis Enabled by Catalyst Design
作者:Nathan J. Adamson、Haleh Jeddi、Steven J. Malcolmson
DOI:10.1021/jacs.9b02637
日期:2019.5.29
surrogate to afford primary amines in a two-step/one-pot process. Examination of chiral catalysts revealed a high degree of reversibility in the C-N bond formation that negatively impacted enantioselectivity. Consequently, an electron-poor ferrocenyl-PHOX ligand was developed to enable efficient and enantioselective enyne hydroamination.
Regioselective Access to 3‐Ethylideneflavanones via Rhodium(I)‐Catalyzed 1,3‐Enyne Hydroacylation/Annulation Cascades
作者:Zhi‐Xin Chang、Fu‐Rong Li、Chengcai Xia、Fei Li、Hong‐Shuang Li
DOI:10.1002/adsc.202001565
日期:2021.3.16
The highly efficient synthesis of 3‐ethylideneflavanones throughsequential rhodium(I)‐catalyzed hydroacylation of terminal aryl‐substituted 1,3‐enynes with chelating aldehydes and annulation is described. This straightforward protocol highlights an unprecedented C3‐regioselective hydroacylation of 1,3‐enynes, excellent functional group compatibility, and complete atom economy.
Stereodivergent Synthesis of Tertiary Fluoride-Tethered Allenes via Copper and Palladium Dual Catalysis
作者:Shao-Qian Yang、Yi-Fan Wang、Wei-Cheng Zhao、Guo-Qiang Lin、Zhi-Tao He
DOI:10.1021/jacs.1c03157
日期:2021.5.19
protocol for the unprecedented stereodivergentsynthesis of tertiary fluoride-tethered allenes bearing a stereogenic center and stereogenic axis via Cu/Pdsynergisticcatalysis. A broad scope of conjugated enynes are coupled with various α-fluoroesters in high yields with high diastereoselectivities and generally >99% ee. In addition, the four stereoisomers of the allene products ensure precise access
halogenated salt, plays a crucial role in the success. Control experiments and theoretical studies disclosed that the four-membered ring transmetallation transitionstates which were stabilized by a halide anion are the key to yields and stereochemical outcomes.
Enantioselective Synthesis of Trisubstituted Allenyl–B(pin) Compounds by Phosphine–Cu-Catalyzed 1,3-Enyne Hydroboration. Insights Regarding Stereochemical Integrity of Cu–Allenyl Intermediates
作者:Youming Huang、Juan del Pozo、Sebastian Torker、Amir H. Hoveyda
DOI:10.1021/jacs.7b13296
日期:2018.2.21
Catalytic enantioselective boron-hydride additions to 1,3-enynes, which afford allenyl-B(pin) (pin = pinacolato) products, are disclosed. Transformations are promoted by a readilyaccessible bis-phosphine-Cu complex and involve commercially available HB(pin). The method is applicable to aryl- and alkyl-substituted 1,3-enynes. Trisubstituted allenyl-B(pin) products were generated in 52-80% yield and