Titanocene-Catalyzed Reductive Domino Epoxide Ring Opening/Defluorinative Cross-Coupling Reaction
作者:Zhiyang Lin、Yun Lan、Chuan Wang
DOI:10.1021/acs.orglett.0c00960
日期:2020.5.1
method for efficient synthesis of gem-difluorobishomoallylic alcohols starting from trifluoromethyl-substituted alkenes and epoxides via a titanocene-catalyzed reductive domino reaction, which consists of a Ti(III)-mediated radical-type ring opening and the following allylic defluorinative cross-coupling reaction via sequential radical addition and β-F elimination. Notably, complete regioselectivity and
Ti-catalyzed regioselective ring-opening alkynylation of epoxides with haloalkynes
作者:Di Zhang、Hao Li、Dong Yi、Shijing Tu、Zhongyu Qi、Siping Wei、Qiang Fu、Haiyan Fu、Xi Du
DOI:10.1016/j.tetlet.2021.153461
日期:2021.11
Ti-catalyzed ring-opening alkynylation of epoxides with haloalkynes has been achieved, allowing an efficient and regioselective entry to various propargylic alcohols in moderate to good yields. The developed protocol features extremely mild reaction conditions, broad substrate scope, varied functional group compatibility, and chemospecificity in the rearrangements of epoxides to aldehydes.
已经实现了环氧化物与卤代炔烃的 Ti 催化开环炔基化,允许以中等至良好的产率有效和区域选择性地进入各种炔丙醇。开发的协议具有极其温和的反应条件、广泛的底物范围、不同的官能团兼容性以及环氧化物重排为醛的化学特异性。
Photo‐Induced Homologation of Carbonyl Compounds for Iterative Syntheses
作者:Hua Wang、Shun Wang、Vincent George、Galder Llorente、Burkhard König
DOI:10.1002/anie.202211578
日期:2022.12.5
A photo-induced Büchner-Curtius-Schlotterbeck type reaction for carbonyl homologation is described. The protocol allows the use of carbonyl compounds as safe and readily available diazo precursors through direct photoexcitation of corresponding N-tosylhydrazone anions. Functionalized aliphatic aldehydes and ketones are prepared in a practical and iterative manner.
Stereoinversion of Unactivated Alcohols by Tethered Sulfonamides
作者:Paul T. Marcyk、Latisha R. Jefferies、Deyaa I. AbuSalim、Maren Pink、Mu‐Hyun Baik、Silas P. Cook
DOI:10.1002/anie.201812894
日期:2019.2.4
remains an undeveloped area of organic synthesis. Moreover, catalytic activation of this difficult electrophile with predictable stereo-outcomes presents an even more formidable challenge. Described herein is a simple iron-based catalyst system which provides the mild, direct conversion of secondary and tertiary alcohols to sulfonamides. Starting fromenantioenriched alcohols, the intramolecular variant
Ligand-Free Nickel-Catalyzed Reductive Allylic Defluorinative Cross-Coupling of α-Trifluoromethyl Alkenes with Epoxides
作者:Chuan Wang、Zhiyang Lin、Yun Lan
DOI:10.1055/s-0040-1707170
日期:2021.9
We report a reductive allylic defluorinative reaction of α-trifluoromethyl alkenes with terminal epoxides, which consists of an iodide-mediated regioselective ring opening and a nickel-catalyzed radical-type cross-coupling, providing diverse tertiary gem-difluorobishomoallylic alcohols in moderate to high yields. Notably, this reaction is conducted under mild conditions and requires no external ligand