The tandem nucleophilic addition–cycloaddition reaction has been developed for the synthesis of functionalized imidazolidine derivatives. A variety of α-iminoesters and aryne precursors were well tolerated under the mild reaction conditions. This asymmetric cycloaddition afforded imidazolidine derivatives with high yields, complete regioselectivities, and excellent diastereo- and enantioselectivities
Cu(<scp>i</scp>)-Catalyzed asymmetric <i>exo</i>-selective synthesis of substituted pyrrolidines <i>via</i> a 1,3-dipolar cycloaddition reaction
作者:Rayhan G. Biswas、Sumit K. Ray、Vinod K. Kannaujiya、Rajshekhar A. Unhale、Vinod K. Singh
DOI:10.1039/d1ob00494h
日期:——
An (R)-DM-BINAP/Cu(CH3CN)4BF4 complex catalyzed exo-selective asymmetric 1,3-dipolarcycloaddition (1,3-DCA) reaction of imino esters with α,β-unsaturated pyrazoleamides has been developed. A series of highly functionalized pyrrolidines with multiple stereogenic centers were obtained with good yields and diastereoselectivities and excellent enantioselectivities (up to 99% ee).
Acid-Base Dual-Functional
Catalysis by Axially Chiral Guanidine in Enantioselective [3+2] Cycloaddition
of Maleate to Schiff Bases as a Precursor of Azomethine Ylides
作者:Masahiro Terada、Megumi Nakano
DOI:10.1055/s-0029-1217345
日期:——
The enantioselective [3+2] cycloaddition reaction of dimethyl maleate with Schiff bases as the precursor of azomethine ylide was developed using axially chiral guanidine catalysts to provide optically active pyrrolidine derivatives. Acid-base dual-functional catalysis by an axially chiral guanidine through double hydrogen-bonding interaction is proposed to give the cycloaddition products in good yields.
Zinc‐Catalyzed Enantioselective [3+2] Cycloaddition of Azomethine Ylides Using Planar Chiral [2.2]Paracyclophane‐Imidazoline N,O‐ligands
作者:Sundaravel Vivek Kumar、Patrick J. Guiry
DOI:10.1002/anie.202205516
日期:2022.8.15
novel [2.2]paracyclophane-derived ligands (UCD-IMPHANOL) possessing central chirality and planar chirality has been developed. These ligands demonstrated excellent enantioselectivities in the asymmetric Zn-catalyzed azomethineylidecycloaddition.
Zn(ii)-catalyzed asymmetric [3 + 2] cycloaddition of acyclic enones with azomethine ylides
作者:Sundaravel Vivek Kumar、Jeremiah Olusegun、Patrick J. Guiry
DOI:10.1039/d4ob00854e
日期:——
The Zn(II)/UCD-Imphanol-catalyzed highly endo-selective [3 + 2] asymmetriccycloaddition of acyclic enones and azomethineylides has been developed. Moderate to high yields (up to 94%) with excellent endo/exo selectivities (99 : 1) and enantioselectivities up to 96.5 : 3.5 er were obtained.
开发了 Zn( II )/UCD-Imphanol 催化的无环烯酮和偶氮甲碱叶立德的高度内选择性 [3 + 2] 不对称环加成反应。获得了中等到高产率(高达 94%),具有出色的内切/外切选择性(99:1)和高达 96.5:3.5 er 的对映选择性。