Aromatic-Amide-Derived Nonbiaryl Atropisomer as Highly Efficient Ligand for Asymmetric Silver-Catalyzed [3 + 2] Cycloaddition

In this work, we have successfully determined that the aromatic amide-derived nonbiaryl atropisomer/silver complex (silver-Xing-Phos) is an effective catalyst system for the solvent-dependent <i>exo</i>-selective cycloaddition of glycine aldimino esters with chalcones or less-reactive methyl cinnamates to give the corresponding chalcone- or cinnamate-derived pyrrolidines with multiple stereogenic centers in good yields and high diastereoselectivities as well as excellent enantioselectivities. Remarkably, it is the first example of highly enantioselective silver-catalyzed [3 + 2] cycloaddition of methyl cinnamates with glycine aldimino esters

Ar-BINMOL–Derived Salan–Cu(II) Complex–Catalyzed Silyl-Reformatsky Reaction of Aromatic Aldehydes

<div><p></p><p>In this work, we have developed a facile protocol with salan–Cu system for the facile and selective synthesis of β-hydroxyesters via silyl-Reformatsky reaction with α-silylester and aldehydes. The screening and optimization of reaction conditions led to the determination of a practical and efficient procedure in which the salan–Cu exhibited promising catalytic activity in dimethylsulfoxide, in which the silyl-Reformatsky reaction of aromatic aldehydes with α-trimethylsilylmethylacetate gave the corresponding β-hydroxyester derivatives in excellent yields (up to 98%) under fluoride-free reaction conditions.</p> </div

Asymmetric Synthesis of Glutamic Acid Derivatives by Silver-Catalyzed Conjugate Addition–Elimination Reactions

The enantioselective construction of a family of chiral glycine-derived aldimino esters is described. The asymmetric tandem conjugate addition–elimination procedure is characterized by its exceptional mild reaction conditions and features with an exquisite enantioselectivity profile using commercially available silver/DTBM-SegPhos catalyst, allowing for the facile preparation of a variety of substituted and chiral glutamic acid derivatives (up to 99% ee) bearing Schiff base in a straightforward manner

Ligand-Controlled Inversion of Diastereo- and Enantioselectivity in Silver-Catalyzed Azomethine Ylide–Imine Cycloaddition of Glycine Aldimino Esters with Imines

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 <i>syn</i>-selective or DTBM-Segphos-induced <i>anti</i>-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