N , O -Acetals derived from α,β-unsaturated β-aryl substituted aldehydes and (1-aminocyclohexyl)methanol were found to undergo a catalytic enantioselective [2 + 2] photocycloaddition to a variety of olefins (19 examples, 54–96% yield, 84–98% ee ). The reaction was performed by visible light irradiation (λ = 459 nm). A chiral phosphoric acid (10 mol %) with an ( R )-1,1′-bi-2-naphthol (binol) backbone served as the catalyst. The acid displays two thioxanthone groups attached to position 3 and 3′ of the binol core via a meta -substituted phenyl linker. NMR studies confirmed the formation of an iminium ion which is attached to the acid counterion in a hydrogen-bond assisted ion pair. The catalytic activity of the acid rests on the presence of the thioxanthone moieties which enable a facile triplet energy transfer and an efficient enantioface differentiation.

Trimethyl orthoacetate and ethylene glycol mono-vinyl ether are employed in iridium-catalyzed enantioselective allylation reactions. The method documented enables their convenient use as surrogates for silyl ketene acetals and silyl enol ethers to prepare γ,δ-unsaturated esters and protected aldehydes with excellent enantioselectivity. The utility of this novel method has been demonstrated by its implementation in a formal enantioselective synthesis of the meroterpenoid (+)-conicol.

Primary allylic amines with enantiomeric excesses from 97 to >99% were prepared by asymmetric transfer hydrogenation of α,β-unsaturated N-(tert-butylsulfinyl)ketimines followed by removal of the sulfinyl group. The effect caused by different substituents at the C═C bond and at the iminic carbon atom on the chemoselectivity of the reduction was studied. The desired enantiomer of the final allylic amine can be synthesized by choosing the sulfinyl group with the appropriate absolute configuration.

Morpholine ketene aminal is employed in iridiumcatalyzedasymmetric allylic alkylation reactions as asurrogate for amide enolates to prepare g,d-unsaturated b-substituted morpholine amides.Kinetic resolution or,alternatively,stereospecific substitution affords the corresponding products in high enantiomeric excess.T he utility of the products generated by this method has been showcased by their further elaboration into amines,k etones,o ra cyl silanes.Ap utative catalytic intermediate (h 3 -allyl)iridium(III) with achiral P, Olefin-ligand was synthetized and characterized for the first time.Supportinginformation and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.

In recent years, photochemical reactions have emerged as powerful transformations which significantly expand the repertoire of organic synthesis. However, a certain lack of selectivity can hamper their application and limit their scope. In this context, a major research effort continues to focus on an improved control over stereo- and chemoselectivity that can be achieved in molecular assemblies between photosubstrates and an appropriate host molecule. In this tutorial review, some recent, representative examples of photochemical reactions have been collected whose unique outcome is dictated by the formation of a molecular assembly driven by non-covalent weak interactions. Graphical Abstract