Update 1 of: BINOL: A Versatile Chiral Reagent

Catalytic asymmetric construction of spiro(γ-butyrolactam-γ-butyrolactone) moieties through sequential reactions of cyclic imino esters with Morita-Baylis-Hillman bromides

Spiro(γ-butyrolactam-γ-butyrolactone): a route to enantioenriched spiro(γ-butyrolactam-γ-butyrolactone) compounds, a valuable motif for drug discovery, was developed by use of a highly efficient copper(I)/TF-BiphamPhos-catalyzed tandem Michael addition-elimination of homoserine lactone derived cyclic imino esters with Morita-Baylis-Hillman (MBH) bromides, followed by treatment with para-toluenesulfonic acid.

Gaseous Ni+ complexes with BINOL derivatives and chiral esters in the gas phase: an experimental and theoretical investigation

The gas-phase behavior of monocationic Ni(II) complexes that contain as building blocks optically pure BINOL derivatives and two chiral hydroxy esters is investigated by means of electrospray ionization (ESI) mass spectrometry. Upon collision-induced dissociation (CID), the complexes containing ethyl 2-hydroxypropionate (ethyl lactate) only lose the ester ligand. The complexes bearing ethyl 3-hydroxybutyrate instead either lose the ester ligands or undergo bond activation followed by elimination of the corresponding β-ketoester (ethyl acetylacetate) as revealed by deuterium labeling. Comparison of the results obtained for com- plexes with different chiralities reveals the operation of a significant stereochemical effect (SE) in the gas-phase dehydrogenation of ethyl 3-hydroxybutyrate by gaseous [(BINOLato)Ni]+ ions. Instead, no substantial differences in the CID patterns for the complexes bearing the ester-substituted BINOL derivative are found. The results provide insights into the gas-phase coordination of metal cations by BINOL derivatives and into the molecular features, which are responsible for gas-phase enantioselective processes. Additional mechanistic aspects are disclosed by exploratory calculations employing density functional theory using the B3LYP method.

Enantioselective addition of boronates to acyl imines catalyzed by chiral biphenols

On the big screen: A chiral biphenol catalyst screening protocol was developed for the rapid identification of enantioselective nucleophilic boronate reactions with acyl imines (see scheme). The approach successfully identified a unique catalyst for the reaction of aryl, vinyl, and alkynyl boronates. Mechanistic studies demonstrate boronate ligand exchange with the catalyst is necessary for activation towards nucleophilic addition.