A practical three-step protocol for the assembly of triazolobenzodiazepine-fused diketopiperazines and hydantoins has been developed. The synthesis of these tetracyclic ring systems was initiated by an Ugi reaction, which brought together all necessary functionalities for further transformations. The Ugi adducts were then subjected to a base-induced ring closing and an intramolecular azide-alky...

An Ugi multicomponent reaction based two-step strategy was applied to generate medium-sized rings. In the first linear expansion phase, a series of diamines reacted with cyclic anhydrides to produce different lengths of terminal synthetic amino acids as the starting material for the second phase. The Ugi-4-center 3-component reaction was utilized to construct complex medium-sized rings (8-11) b...

We have synthesised a novel oxanorbornene β-aminoacid derivative and employed it in a stereoselective Ugi reaction. Hypothesis regarding the mechanism taking place during the reaction have been made and validated through the determination of the relative and absolute configuration of the Ugi adducts. Use of the correct choice of solvents can increase stereoselection. The resulting bicyclic pept...

A wide range of 5-substituted thiazoles are easily accessible via cross coupling of thiazolyl triflates. These activated thiazoles can be obtained by Ugi reactions using thioacids (thio-Ugi-reaction) and subsequent cyclisation of the endo thiopeptides formed with triflic anhydride. In addition, cyclisations with acyl halides give rise to 5-acyloxysubstituted derivatives.

A solution phase synthesis of peptide nucleic acid monomers and dimers was developed by using microwave-promoted Ugi multicomponent reactions. A mixture of a functionalized amine, a carboxymethyl nucleobase, paraformaldehyde and an isocyanide as building blocks generates PNA monomers which are then partially deprotected and used in a second Ugi 4CC reaction, leading to PNA dimers. Conformationa...

The synthesis of nonsymmetrical polyamines (PAs) has, up to now, been problematic due to lengthy synthetic procedures, lack of regioselectivity, and very poor atom economy. An innovative synthetic protocol for nonsymmetrical PAs using a modified Ugi reaction ( N-split Ugi) which simplifies the synthesis of these tricky compounds is described. We believe that this new synthesis may open the door...

A regioselective approach for the synthesis of pyrrolopyridinones and pyrroloazepinones is reported employing an Ugi reaction followed by a gold(I) or platinum(II) catalyzed intramolecular hydroarylation.