Investigation of the Mitsunobu Reaction of BINOL and Cinchona Alkaloids: Inversion or Retention of Configuration?

<div><p></p><p>An efficient approach toward the construction of multistereogenic binaphthol (BINOL)–derived alkaloids with C₂-axial and sp³ central chirality has been accomplished. The reaction of BINOL and cinchona alkaloids was occurred smoothly under the Mitsunobu conditions, which led to the synthesis of a new family of complicated functional molecules based on chiral BINOL and cinchona alkaloids. In addition, on the basis of the experimental results, we provided a possible explanation for the intramolecular tertiary amine-induced retention of configuration at C9 of cinchona alkaloids while the inversion of configuration was observed with general alcohols under classic Mitsunobu 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

3‑Alkyl-2-pyridyl Directing Group-Enabled C2 Selective C–H Silylation of Indoles and Pyrroles via an Iridium Catalyst

An iridium-catalyzed, directing group-enabled site selective intra- and intermolecular silylation of indoles and pyrroles with hydrosilanes has been developed under ligand-free conditions. Fine-tuning of the removable 3-alkyl-2-pyridyl directing group was found to be crucial for achieving high yields for C2-silylated indole and pyrrole products. Moreover, the scalability was demonstrated, and further transformations of the silylation products were achieved

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