Synthesis and application of chiral β‐amino disulfides as ligands for the enantioselective addition of diethylzinc to aldehydes

Abstract

A new class of chiral beta-amino disulfides was synthesized from readily available and inexpensive starting materials by a straightforward method and their abilities as ligands were examined in the enantioselective addition of diethylzinc to aldehydes. Enantiomeric excesses of up to 99% have been obtained using 0.5 mol % of the chiral catalysts.

Modular amino acids and β‐amino alcohol‐based chiral ligands for enantioselective addition of diethylzinc to aromatic aldehydes

“…Based on previous works in the field of the enantioselective addition diethylzinc to aldehydes,1–10 the Zn (II) complex might play a bifunctional role in this reaction 7b. As shown in Fig.…”

“…Synthesis of a chiral secondary alcohol by enantioselective addition of diorganozinc to an aldehyde is one of the most successful areas in the field of asymmetric CC bond formation reactions 1. Therefore, a remarkable number of chiral ligands such as diols,2 diamines,3 aminothiols,4 aminodisulfides,5 amino alcohols6 diphosphoryldiols,7 phosphoramides8 and aminodiselenides9 have been developed for the enantioselective addition of diethylzinc to aldehydes. Despite the achievements made in this field of the addition of aldehydes, it has not yet reached the level of practicability that is required for a synthetically useful catalytic system.…”

Microwave-assisted solvent- and catalyst-free synthesis of allylic thioetheres from allylic alcohols

“…4 However, these methodologies require either Lewis or Brønsted acid to catalyze the synthesis of allylic thioetheres generating unwanted byproduct, beyond expensive cost of these catalyst. In line with our interest in organochalcogenide 5 herein we report the synthesis of allylic thioetheres under microwave irradiation and solvent-and catalyst-free conditions (Scheme 1).…”

Mild and selective silicon-mediated access to enantioenriched 1,2-mercaptoamines and β-amino arylchalcogenides

“…β-Aminothiols find wide application in synthetic organic chemistry, medicinal chemistry, and catalysis. 3 They are commonly used as intermediates for the synthesis of biologically relevant molecules, such as peptides, 4 thiazolidines, 5 thiazolines, 6 thiomorpholines, 7 and thiazepines.…”