A highly diastereo- and enantioselective silver-catalyzed azomethine ylide-imine (AYI) cycloaddition reaction of glycine aldimino esters with imines was developed in which the Xing-Phos-controlled syn-selective or DTBM-Segphos-induced anti-selective AYI cycloaddition reaction could be applied to the synthesis of a variety of stereodivergent 1-alkyl-2,5-substituted imidazolidines with high yields and excellent enantioselectivities (up to 99% ee) as well as good diastereoselectivities (up to 99:1 dr) under mild reaction conditions.
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http://dx.doi.org/10.1021/acs.orglett.8b00702 | DOI Listing |
Chem Sci
August 2023
Research Center for Molecular Recognition and Synthesis, Department of Chemistry, Fudan University 220 Handan Lu Shanghai 200433 P. R. China
Cycloaddition is a fundamental transformation, featuring the assembly of complex cyclic molecules with multiple stereocenters. We report here a silver-catalyzed [3+2]-cycloaddition of 2,3-disubstituted cyclobutenones with an array of azomethine ylide precursors iminoesters, furnishing azabicycles in good yields and enantioselectivities. Up to three contiguous all-carbon quaternary centers, including two angular stereocenters, could be constructed efficiently, due to high reactivity of strained cyclobutenones.
View Article and Find Full Text PDFChem Asian J
August 2022
Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga Bunkyo-ku, 112-8551, Tokyo, Japan.
An unprecedented Ag-catalyzed exo'-selective [3+2] cycloaddition of imino esters with 4-benzylidene-2,3-dioxopyrrolidines is described. The reaction was efficiently catalyzed by Ag/(R, S )-ThioClickFerrophos (TCF) leading to the construction of the corresponding spirobipyrrolidine scaffolds in excellent enantio- and diastereoselectivities. This reaction is the first example of a silver-catalyzed exo'-selective asymmetric [3+2] cycloaddition, as well as the first exo'-selective spirobipyrrolidine construction via a [3+2] cycloaddition process using imino esters.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
June 2022
College of Pharmaceutical Sciences, and Hangzhou Institute of Innovative Medicine, Zhejiang University, Hangzhou, 310058, China.
In contrast to the well-established [3+2] cycloaddition reactions, the catalytic enantioselective [3+n] (n≥3) cycloaddition reaction of activated isocyanides for the preparation of six-membered or larger ring systems has remained underdeveloped. Herein, we report the first example of highly diastereo- and enantioselective [3+3] cycloaddition of activated isocyanides with azomethine imines. By employing silver catalysis, a wide range of biologically important bicyclic 1,2,4-triazines were obtained in high yields (up to 99 %) with good to excellent stereoselectivities (up to >20 : 1 dr, 99 % ee).
View Article and Find Full Text PDFOrg Lett
May 2018
Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education , Hangzhou Normal University, Hangzhou 311121 , P. R. China.
A highly diastereo- and enantioselective silver-catalyzed azomethine ylide-imine (AYI) cycloaddition reaction of glycine aldimino esters with imines was developed in which the Xing-Phos-controlled syn-selective or DTBM-Segphos-induced anti-selective AYI cycloaddition reaction could be applied to the synthesis of a variety of stereodivergent 1-alkyl-2,5-substituted imidazolidines with high yields and excellent enantioselectivities (up to 99% ee) as well as good diastereoselectivities (up to 99:1 dr) under mild reaction conditions.
View Article and Find Full Text PDFChemistry
December 2016
Abteilung Chemische Biologie, Max-Planck-Institut für Molekulare Physiologie, Otto-Hahn-Straße 11, 44227, Dortmund, Germany.
A silver-catalyzed highly enantioselective 1,3-dipolar cycloaddition reaction of α-silylimines with pyrone-based trisubstituted olefins was developed affording bi- and tricyclic α-quaternary-carbon-rich pyrano-pyrrolidines in excellent yields. The tricyclic benzopyrone adducts thus obtained were efficiently transformed into highly complex tetracyclic scaffolds supporting four consecutive stereogenic centers with three quaternary carbons.
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