Access to luminescent mesophases of gold(I) chiral complexes by thermal or mechanic stimuli. The role of the tertiary carbon

Chiral gold(I) isocyanide complexes [Au(p-C6F4OR1)(p-CNC6H4(O2CC6H4(OR2)] with R1, R2 or both being (R)-2-octyl, display an interesting and unprecedented response to mechanical or thermal stress. For all the complexes, heating leads to...

Design of Iridium N-Heterocyclic Carbene Amino Acid Catalysts for Asymmetric Transfer Hydrogenation of Aryl Ketones

A series of chiral complexes of the form Ir(NHC)2(aa)(H)(X) (NHC = N-heterocyclic carbene, aa = chelated amino acid, X = halide) was synthesized by oxidative addition of -amino acids to iridium(I) bis-NHC compounds and screened for asymmetric transfer hydrogenation of ketones. Following optimization of the reaction conditions, NHC, and amino acid ligands, high enantioselectivity was achieved when employing the Ir(IMe)2(l-Pro)(H)(I) catalyst (IMe = 1,3-dimethylimidazol-2-ylidene), which asymmetrically reduces a range of acetophenone derivatives in up to 95% enantiomeric excess.

Design of Iridium N-Heterocyclic Carbene Amino Acid Catalysts for Asymmetric Transfer Hydrogenation of Ketones

A series of chiral complexes of the form Ir(NHC)2(aa)(H)(X) (NHC = N-heterocyclic carbene, aa = chelated amino acid, X = halide) was synthesized by oxidative addition of -amino acids to iridium(I) bis-NHC compounds and screened for asymmetric transfer hydrogenation of ketones. Following optimization of the reaction conditions, NHC, and amino acid ligands, high enantioselectivity was achieved when employing the Ir(IMe)2(l-Pro)(H)(I) catalyst (IMe = 1,3-dimethylimidazol-2-ylidene), which asymmetrically reduces a range of acetophenone derivatives in up to 95% enantiomeric excess.

Planar Chiral Boron Difluoride Complexes showing Circularly Polarized Luminescence

A family of novel boron difluoride complexes based on [2.2]paracyclophane has been designed and facilely synthesized. These chiral complexes have been demonstrated have excellent chiroptical properties, with strong Cotton effects...

Visible-Light-Promoted Asymmetric Catalysis by Chiral Complexes of First-Row Transition Metals

This short review presents an overview of visible-light-driven asymmetric catalysis by chiral complexes of first-row transition metals. The processes described here include dual catalysis by a chiral complex of copper, nickel, cobalt or chromium and an additional photoredox or energy-transfer catalyst, and bifunctional catalysis by a single chiral copper or nickel catalyst. These methods allow valuable transformations with high functional group compatibility. They provide stereoselective construction of carbon-carbon or carbon-heteroatom bonds under mild conditions, and produce a diverse range of previously unknown enantio-enriched compounds.

Application of Infrared Multiple Photon Dissociation (IRMPD) Spectroscopy in Chiral Analysis

In recent years, methods based on photodissociation in the gas phase have become powerful means in the field of chiral analysis. Among them, infrared multiple photon dissociation (IRMPD) spectroscopy is a very attractive one, since it can provide valuable spectral and structural information of chiral complexes in addition to chiral discrimination. Experimentally, the method can be fulfilled by the isolation of target diastereomeric ions in an ion trap followed by the irradiation of a tunable IR laser. Chiral analysis is performed by comparing the difference existing in the spectra of enantiomers. Combined with theoretical calculations, their structures can be further understood on the molecular scale. By now, lots of chiral molecules, including amino acids and peptides, have been studied with the method combined with theoretical calculations. This review summarizes the relative experimental results obtained, and discusses the limitation and prospects of the method.