A direct catalytic substitution of various allylic and benzylic alcohols with synthetically useful, but acid-sensitive Boc, Bus, and Dios protected amine nucleophiles, which have not been well utilized for Lewis acid catalysis, with various functionalities (OTBS, OTHP, etc.) was efficiently catalyzed by 1 mol% of Au(III) under mild conditions.
Synthesis of <i>N</i>-Boc-Propargylic and Allylic Amines by Reaction of Organomagnesium Reagents with <i>N</i>-Boc-Aminals and Their Oxidation to <i>N</i>-Boc-Ketimines
作者:Taichi Kano、Ryohei Kobayashi、Keiji Maruoka
DOI:10.1021/acs.orglett.5b03446
日期:2016.1.15
N-Boc-protected propargylic and allylic amines were synthesized by the reaction between N-Boc-aminals and organomagnesiumreagents through the in situ generated N-Boc-imine intermediates. The obtained N-Boc-propargylic amines could be readily converted into unprecedented N-Boc-ketimines by oxidation with manganese dioxide.
Decarboxylative Hydroalkylation of Alkynes via Dual Copper-Photoredox Catalysis
作者:Marco M. Mastandrea、Santiago Cañellas、Xisco Caldentey、Miquel A. Pericàs
DOI:10.1021/acscatal.0c01742
日期:2020.6.5
base. The developed methodology has been applied to the stereoselective coupling of primary, secondary, and tertiary alkyl radicals with (hetero)aromatic terminal alkynes. As an additional practicality, similar reaction conditions allowed for the use of aromatic amines as radical precursors in a cross dehydrogenativecoupling for the direct vinylation of inactivated C–H bonds.
Mechanistic dichotomy in the solvent dependent access to <i>E vs. Z</i>-allylic amines <i>via</i> decarboxylative vinylation of amino acids
作者:Samir Manna、Shunta Kakumachi、Kanak Kanti Das、Youichi Tsuchiya、Chihaya Adachi、Santanu Panda
DOI:10.1039/d2sc02090d
日期:——
donor–acceptor based photocatalysts. The solvent-dependent access to E vs. Z-allylic amines was achieved via decarboxylative vinylation of amino acids with vinyl sulfones. Detailed experimental studies have been conducted to understand the role of the solvent in the reactivity and stereoselectivity of the vinylation reactions.
Organophotocatalytic Radical–Polar Cross-Coupling of Styrylboronic Acids and Redox-Active Esters
作者:Allan J. B. Watson、Jeremy Brals、Nicholas D’Arcy-Evans、Thomas M. McGuire
DOI:10.1055/a-2179-6570
日期:2024.1
We report the development of a radical–polar cross-coupling reaction using styrylboronic acids and redox-active esters under organophotoredox catalysis. The reaction proceeds through a formal polarity-mismatched radical addition. The use of an organic photocatalyst permitted very low loadings of the electron-shuttle additive and accelerated reaction times compared with established processes. The scope