Conformational Selection in Enzyme-Catalyzed Depolymerization of Bio-based Polyesters.

Enzymatic degradation of polymers holds promise for advancing towards a bio-based economy. However, bulky polymers presents challenges in accessibility for biocatalysts, hindering depolymerization reactions. Beyond the impact of crystallinity, polymer chains can reside in different conformations affecting binding efficiency to the enzyme.

Access to 1-indolyltetrahydro-β-carbolines via metal-free cross-dehydrogenative coupling: the total synthesis of eudistomin U, isoeudistomin U and 19-bromoisoeudistomin U.

A highly selective and captivating metal-free cross-dehydrogenative coupling for the cross-coupling of two reactive nucleophiles such as tetrahydro-β-carboline and indoles is developed. A series of 1-indolyltetrahydro-β-carboline derivatives were synthesized in excellent to moderate yields. Temperature, time and concentration control resulted in mono indolylation selectively.

Metal-Free C-H Functionalization and Aromatization Sequence for the Synthesis of 1-(Indol-3-yl)carbazoles and Total Synthesis of 7-Bromo-1-(6-bromo-1 H-indol-3-yl)-9 H-carbazole.

An operationally simple, metal-free, cost-effective, and mild oxidative cross-coupling protocol for the synthesis of 1-indolyl tetrahydrocarbazoles to afford 1-(indol-3-yl)carbazoles is developed. N-Chlorosuccinimide is used as a mild oxidant for the functionalization of the 1-position of tetrahydrocarbazoles, aromatization of which furnished 1-(indol-3-yl)carbazoles in good to moderate yields without employing protection/deprotection strategy. A naturally rare dibromo 1-(indol-3-yl)carbazole alkaloid was synthesized for the first time in two steps with an overall yield of 64% by applying the same methodology.

Insight into Copper Catalysis: In Situ Formed Nano CuO in Suzuki-Miyaura Cross-Coupling of Aryl/Indolyl Boronates.

A ligand-free copper catalyzed Suzuki-Miyaura coupling of 3,5-diiodopyridine with aryl and indole boronates has been explored in good to excellent yields. In situ generation of nano-CuO from CuCl under the reaction conditions has been discovered for the first time. The generality of the reaction was further demonstrated by the arylation of 5-iodopyrimidine, iodopyridines, iodobenzenes, and diiodobenzenes and resulted in good to moderate yields.