Modular, Flexible, and Stereoselective Synthesis of Pyrroloquinolines: Rapid Assembly of Complex Heterocyclic Scaffolds

Abstract

A novel 1,2-dinucleophile engages two imines in a sequential vinylogous Mannich-Mannich-Pictet-Spengler process to generate complex hexahydropyrrolo[3,2-c]quinolines in a one-pot operation. This methodology provides a rapid, highly modular, and flexible access toward a wide range of products and forms four new σ-bonds and chiral centers each. The diastereoselectivity may be inverted by fine-tuning of reaction conditions and the electronic nature of the imines.

A highly enantioselective, organocatalytic [3+2]-cycloannulation reaction towards the de novo-synthesis of 1-cyclopentenyl-α-keto esters

“…Under identical reaction conditions, the Hayashi catalyst 3b furnished an increased yield of 78% for the mixture of regioisomers from which the desired pure γproduct 4a was isolated with 63% yield and 99:1-enantioselectivity suggesting this catalyst for further studies (entry 7). In addition we tested other acidic cocatalysts in combination with 3b which led, however, to inferior results (entries [8][9].…”

Continuous Flow Synthesis of Highly Substituted Tetrahydrofurans

“…We recently reported a highly diastereoselective BF 3 · OEt 2 mediated, novel, one‐pot synthesis of 2,3,5‐trisubstituted tetrahydrofurans employing the readily available bis(silyl)dienediolate 1 recently established in our group …”

A Complex Catalytic Reaction Caught in the Act: Intermediates and Products Sampling Online by Liquid μ‐Beam Mass Spectrometry and Theoretical Modeling

“…In the currents tudy we highlight the first application of the approach on an important typeo f modularm ulticomponent reaction as at est case for the technique. [21][22][23][24] We have recently studied some details of the overall reactiond isplayed in Scheme 1, which belongs to af amily of recently developedr eaction schemes to efficiently build up complexo rganic structures. The products and intermediates, as well as the reaction mechanisms are investigatedh ereb y means of laser desorption liquid m-beam mass spectrometry supported by quantum chemical calculations.…”