A novel method for the synthesis of 3‐iodoquinolines was developed by copper‐catalyzed tandem annulation from diaryliodoniums, nitriles, and 1‐iodoalkynes. It is a method that is characterized by the most convenient operation and wide molecular diversity.
α‐Allenols were catalytically transformed into dihydrofurans in the presence of platinum dichloride. Notably, using platinum dichloride along with silver triflate as the catalytic system, α,β‐unsaturated ketones were obtained. Therefore, the role of the silver salt may not just consist in the activation of the platinum precatalyst.
The amination of racemic α‐chiral aldehydes, 2‐phenylpropanal derivatives, was investigated employing ω‐transaminases. By medium and substrate engineering the optical purity of the resulting β‐chiral chiral amine could be enhanced to reach optical purities up to 99% ee. Using enantiocomplementary ω‐transaminases allowed us to access the (R)‐ as well as the (S)‐enantiomer in most cases. It is important to note that the stereopreference of the ω‐transaminases found for α‐chiral aldehydes did not correlate with the stereopreference previously observed for the amination of methyl ketones. In one case the stereopreference switched even upon exchanging a methyl substituent to a methoxy group.
The copper‐catalyzed intramolecular diastereoselective trifluoromethylcycloetherification of homoallylic alcohols with Togni’s reagent as trifluoromethylating reagent was realized under mild conditions. Various trifluoromethylated tetrahydrofurans were synthesized in moderate to good yields. Moreover, a wide range of common functional groups was tolerated.
Densely functionalized polyether macrocycles can be prepared in one pot in yields up to 60% by the rhodium(II)‐catalyzed decomposition of methyl diazoacetoacetate in the presence of a variety of substituted or unsaturated 5‐ and 6‐membered ring cyclic ethers. A comprehensive analysis of the solid state conformations of the macrocyclic geometries is detailed as well as novel mechanistic insights about the multi‐component condensation reaction.
An efficient dehydrogenative Diels–Alder (DHDA) reaction of prenyl derivatives with 2,3‐dichloro‐5,6‐dicyanobenzoquinone (DDQ) has been developed under mild conditions, leading to a series of cyclohexene derivatives with good to excellent yields and excellent diastereoselectivity.
