Domino gold-catalyzed rearrangement and fluorination of propargyl acetates
作者:Teresa de Haro、Cristina Nevado
DOI:10.1039/c002679d
日期:——
A combination of IPrAuNTf(2) as catalyst in the presence of Selectfluor has been successfully used for the high yielding synthesis of alpha-fluoroenones via 1,3-acyloxy rearrangement of propargyl acetates followed by Csp(2)-F bond formation, likely involving a redox Au(I)/Au(III) catalytic cycle.
The copper-catalyzed reductive Ireland–Claisen rearrangement of propargylic acrylates led to 3,4-allenoic acids. The use of silanes or pinacolborane as stoichiometric reducing agents and triethylphosphite as a ligand facilitated the divergent and complementary selectivity for the synthesis of diastereomeric anti- and syn-rearranged products, respectively. Copper-catalyzed reductive Ireland–Claisen rearrangement
Dehydrative Cp*Co(III)-Catalyzed C–H Bond Allenylation
作者:Malay Sen、Pardeep Dahiya、J. Richard Premkumar、Basker Sundararaju
DOI:10.1021/acs.orglett.7b01415
日期:2017.7.21
unprecedented reactivity of Cp*Co(III) for the synthesis of tetrasubstituted allenes under mild conditions is disclosed. Electron-rich and highly nucleophilic cobalt facilitates the dehydrative C–H bond allenylation directly from propargylic alcohols without any derivatization. The reaction proceeds via reversible cyclometalation followed by alcohol-directed regioselective alkyne insertion and β-hydroxy elimination
The combination of Mo and cationic Au catalysts dramatically accelerated the rearrangement of diverse propargyl alcohols, which includes a short reaction time, mild conditions, and high product yields. A practical application to the highly challenging primary propargyl alcohols and the N-alkynyl amides is achieved.
Alkoxide-Catalyzed Addition of Terminal Alkynes to Ketones