Highly efficient synthesis of β-amino esters via Mannich-type reaction under solvent-free conditions using ZnCl_2 catalyst

β-Amino esters were synthesized via ZnCl2-catalyzed Mannich-type reaction of imines and malonate esters under solvent-free conditions in 6 min. The β-amino ester was converted into the corresponding aspartic acid derivatives.

Synthesis of Pyrrole-Imidazole Polyamide

One simple and versatile method is established far the synthesis of DNA recognition molecules-polyamides containing alternating N-methylpyrrole and N-methylimidazole without necessitating NH2- group protection.

Cleavable Cys labeling directed Lys site-selective stapling and single-site modification

Site-selective modification of peptide/protein is a vital approach to disclose post-translational modifications(PTMs) and plays a crucial role in chemical biology, as well as drug development. Compared with synthetic and chemical biology methods, chemical modification of native peptide/protein provides a more versatile approach to achieve late-stage diversification for functional studies. Lysine featured high nucleophilicity, frequency, and solvent accessibility, making its site-selective modification important but elusive. Herein, we reported a visible-light-driven and Cys-directed Lys site-selective stapling approach for peptide/protein. By cleavable Cys anchoring, site-selective Lys single-site modification was achieved, and this method could be applied to multi-functionalization.

Asymmetric synthesis of tetrahydropyran[3,2-c]quinolinones via an organocatalyzed formal[3+3]annulation of quinolinones and MBH 2-naphthoates of nitroolefin

An efficient asymmetric and enantio-swithchable organocatalytic[3+3]annulation reaction using MBH-2-naphthoates of nitroalkenes and 4-hydroxyquinolin-2(1H)-ones has been developed.Densely substituted tetrahydropyrano[3,2-c]qui noli nones scaffolds with two adjacent stereogenic centers are obtained with high yield(up to 95%yield)and good stereoselectivities(up to>20:1 dr and 96%ee)in an enantio-switchable manner.Furthermore,gram scale synthesis was achieved and the nitro group could easily transform into an amino group without any appreciable loss in the diastereo-and enantioselectivity.

On-resin peptide modification of methionine residue by employing 2-bromoacetate derivatives

On-resin peptide modification renders an easy-to-operate method that combines solid-phase peptide synthesis efficiency and avoids tedious purification procedures. Herein, we report the transition-metal-free and redox-neutral approach for solid-phase Met diversification with substrate diversity, which could be applied to synthesize cyclic peptides of different sizes.

Chemoselective Dual Functionalization of Phenols via Relay Catalysis of Borane with Different Forms

A highly efficient and chemoselective dual functionalization of unprotected phenols withα-orβ-hydroxyl acids is presented.A variety of valuable benzofuranones and dihydrocoumarins are delivered in moderate to high yields.Density functional theory(DFT)calculations and control experiments indicate that an untypical Friedel–Crafts alkylation and the subsequent lactonization are catalyzed by the Lewis acid form and the Brønsted acid form of borane,respectively.Gram-scale experiments and late-stage functionalization of complex molecules have been performed to highlight the utility of this reaction.