The development and application of chiral trisoxazolines in asymmetric catalysis and molecular recognition

Abstract

The development of suitable ligands that upon coordination to a metal facilitate enantioselective reactions or are able to selectively recognize a molecule are fundamental endeavours in organic chemistry. Chiral ligands that contain one or two oxazoline groups have been extensively studied and applied successfully to many metal catalyzed reactions. Accordingly, the development and application of chiral trisoxazolines has received increasing attention in the last decade. This tutorial review covers the synthetic methods for the preparation of chiral trisoxazolines, the application of chiral trisoxazolines in asymmetric catalysis and molecular recognition.

Shaping and Enforcing Coordination Spheres: The Implications of C3 and C1 Chirality in the Coordination Chemistry of 1,1,1‐Tris(oxazolinyl)ethane (“Trisox”)

“…The trisox ligand, which we introduced recently, is the first and thus far only trisoxazoline [35] for which facial coordination to transition metals has been firmly established and which therefore qualifies for the generation of C 3 -chiral complexes. The adaptability of the ligand to various types of metal centers has been comprehensively studied in this work.…”

Exploiting Threefold Symmetry in Asymmetric Catalysis: The Case of Tris(oxazolinyl)ethanes (“Trisox”)

“…[19] A trisoxazoline based on Kemps triacid (3) was reported by Bolm and co-workers, [20] whilst such systems with a benzene backbone (4) were reported by Ahn and collaborators. [21] The latter were found to be very selective for the recognition of a-chiral primary ammonium ions as well as enantioselective catalysts for the Michael reaction between methyl phenylacetate and methyl acrylate in the presence of tBuOK.…”

“…(18) and its conversion to the mono (19) and (possibly) dicationic (20) catalysts by alkyl abstraction www.chemeurj.org polymerisation activity increases from lutetium to thulium, and then subsequently decreases with increasing ionic radius of the metal. However, none of the activities are comparable to those observed with the scandium congener [Sc(iPrtrisox)A C H T U N G T R E N N U N G (CH 2 SiMe 3 ) 3 ] described above.…”

“…These trisoxazoline ligands have been successfully employed in a range of highly enantioselective catalytic transformations. [19] First Cyclisation and Then Assembly of the Ligand Backbone: A Modular Synthesis of C 3 -and…”

Synthesis, Characterization and Antimicrobial Activity of Novel Pharmacophores Incorporating Imidazoline-Oxazoline Scaffold

“…8 Synthetic 2-oxazolines and 2-imidazolines are not only useful in biological applications, but also have found use as ligands in coordination chemistry. [9][10][11][12][13][14] The incidences of drug resistance of microorganisms to antibacterial agents were constantly reported for the past few years. Subsequently, there is an urgent need for the development of new drug molecules with newer targets, more potent, selective non-traditional antimicrobial agents and with an alternative mechanism of action.…”