Asymmetric Organocatalysis

Enantioselective Organocatalyzed Synthesis of 2-Amino-3-cyano-4H-chromene Derivatives

“…In the last years, organocatalysis has appeared as an efficient alternative tool to yield enantiopure compounds, through different kind of activation [18][19][20][21]. In this respect, although numerous organocatalyzed racemic syntheses of this family of compounds can be found in the literature [22][23][24][25][26][27][28][29][30][31][32][33], only scarce examples following an enantioselective approach have been reported to date [34].…”

An Ionic Liquid Solution of Chitosan as Organocatalyst

“…The yellow solid was obtained in different yields (see Table 1) and as a mixture of diastereomers after chromatography on silica gel (petrolether/ethyl acetate: 60/40). The diasteroemeric ratio was determined by 1 H-NMR analysis. The enantiomeric excess of the product was determined by HPLC analysis (Daicel AD-H column, flow: 0.8 mL/min, n-heptane/i-PrOH: 90/10 and AD-H column, flow: 0.5 mL/min/i-PrOH: 98/2).…”

“…The research field of organocatalysis has in less than a decade become a well-established research field [1,2]. Organocatalysts can be categorized into Brønsted acids, Brønsted bases, Lewis acids and Lewis bases [3].…”

Thiourea derivatives of Tröger’s base: synthesis, enantioseparation and evaluation in organocatalysis of Michael addition to nitroolefins

“…While simple molecules such as derivatives of proline have been receiving a great deal of attention due to their availability, considerable effort has been directed towards searching for novel chiral scaffolds for asymmetric organocatalysis. 1 Tröger's base 1 is a chiral diamine bearing two stereogenic bridge-head nitrogen atoms ( Figure 1). The two aromatic rings fused to the central bicyclic framework are almost perpendicular to each other, creating a rigid, V-shaped C 2 -symmetrical molecular scaffold with a distance of ca.…”