A Thorough Study on the Photoisomerization of Ferulic Acid Derivatives

AbstractA thorough study on the (E) to (Z) photoisomerization of ferulic acid derivatives (esters, amides of all types, and ketones) was carried out. At the photostationary state, only aliphatic or benzylic tertiary amides reach a nearly complete conversion of (E) isomers into the (Z) ones, whereas for esters, primary and secondary amides or aromatic tertiary amides mixtures of (Z)/(E) ranging from 7 : 93 to 72 : 28 are observed. Ketones show rather limited photoisomerization. However, (Z) ketones may be obtained by the reaction of organometal compounds with an isomerized (Z) Weinreb amide

Multicomponent Synthesis of Polyphenols and Their In Vitro Evaluation as Potential \u3b2-Amyloid Aggregation Inhibitors

While plant polyphenols possess a variety of biological properties, exploration of chemical diversity around them is still problematic. Here, an example of application of the Ugi multicomponent reaction to the combinatorial assembly of artificial, yet \u201cnatural-like\u201d, polyphenols is presented. The synthesized compounds represent a second-generation library directed to the inhibition of \u3b2-amyloid protein aggregation. Chiral enantiopure compounds, and polyphenol-\u3b2-lactam hybrids have been prepared too. The biochemical assays have highlighted the importance of the key pharmacophores in these compounds. A lead for inhibition of aggregation of truncated protein A\u3b2pE3-42 was selected

Ketene 3\u2010Component Staudinger Reaction (K\u20103CSR) to \u3b2\u2010Lactams: A New Entry in the Class of Photoinduced Multicomponent Reactions

The Staudinger synthesis of \u3b2-lactams from imines and ketenes has been conducted photochemically only in very limited cases. Recent advances in the visible light mediated Wolff rearrangement of diazoketones allowed us to perform, for the first time, a 3-component Staudinger reaction, by mixing aldehydes, amines and diazoketones in the dark and switching the light on after imine formation. The new photoinduced reaction parallels the classic methods in terms of efficiency/selectivity and adds to the existing multicomponent approaches for the preparation of combinatorial libraries of compounds. A thorough optimization of the reaction conditions was performed both for the classic two component reaction and for the novel three component version of the photoinduced Staudinger reactio

Integrating biocatalysis and multicomponent reactions

While often multicomponent reactions (MCR) are used for the diversity-oriented synthesis of racemic (or achiral) molecular entities, this short review describes two alternative approaches for accessing enantiopure products exploiting the power of biocatalysis. Enzymes or microorganisms may be used for preparing enantiopure MCR inputs or for resolving racemic (or achiral) MCR adducts