Organocatalysis meets chip MS: By integrating asymmetric organocatalysis and analysis on a chip (see picture), optimization of reactions can be achieved with minimal consumption of resources in a short period of time.

No abstract

The first catalytic, enantioselective vinylogous Mannich reaction of acyclic silyl dienolates is reported. A second-generation 2,2'-dihydroxy-1,1'-binaphthyl (BINOL)-based phosphoric acid has been developed and further optimized as an enantioselective organocatalyst. Upon protonation of the imines, chiral contact ion pairs are generated in situ and attacked highly diastereoselectively by the nucleophile. gamma-Substituted silyl dienolates that lead to more highly substituted Mannich products with a second stereogenic center in good diastereoselectivity have been employed in these reactions. The reaction path has been elucidated with NMR spectroscopy and mass spectrometry, which suggest that the protic reaction medium found to be optimal in these reactions serves to trap the cationic silicon species as silanol. A crystal structure of a phosphoric acid bound imine was obtained that provides insight into the binding mode and a rationale for the stereochemical course of the reaction.

Vinylketene silyl N, O-acetals undergo chiral phosphoric acid-catalyzed, vinylogous Mukaiyama-Mannich reactions with imines and afford delta-amino-alpha,beta-unsaturated amides in typically good yields, complete gamma-regioselectivity, and up to 92% ee with catalyst loadings of as low as 1 mol %. The Mannich products can be readily manipulated to furnish valuable synthetic intermediates.

A palladium-catalyzed intermolecular cross-coupling of two aryl iodides is reported, giving polycyclic ring systems with a high level of convergence and efficiency.