Organocatalysts containing primary−secondary amine based on bispidine and amino acid have been designed to catalyze the asymmetric direct aldol reaction of functionalized ketones including α-keto phosphonates, esters, as well α,α-dialkoxy acceptors. The corresponding products with chiral tertiary alcohols were obtained in moderate high yields (up 97%) enantioselectivities 98% ee). A theoretical study transition structures demonstrated that protonated piperidine was important for reactivity...

Here we report an iridium-catalyzed asymmetric umpolung allylation of imines as a general approach to prepare 1,4-disubstituted homoallylic amines, fundamental class compounds that are hitherto not straightforward obtain. This transformation proceeds by cascade involving intermolecular regioselective 2-azaallyl anions and following 2-aza-Cope rearrangement, utilizes easily available reagents catalysts, tolerates substantial scope substrates, readily leads various enantioenriched, primary amines.

Described here is an enantioselective approach of making chiral, β-substituted homoallylic organoboronic esters. In the presence LiOtBu and a catalytic amount silver salt, commercial bis[(pinacolato)boryl]methane participated in iridium-catalyzed asymmetric allylation reactions, delivered "CH2B(pin)" group, yielded title compounds from allylic carbonates. The synthetic utility prepared chiral organoboronates was demonstrated by their conversion to other important classes compounds.

This study was aimed to design the first dual-target small-molecule inhibitor co-targeting poly (ADP-ribose) polymerase-1 (PARP1) and bromodomain containing protein 4 (BRD4), which had important cross relation in global network of breast cancer, reflecting synthetic lethal effect. A series new BRD4 PARP1 inhibitors were discovered synthesized by fragment-based combinatorial screening activity assays that together led chemical optimization. Among these compounds, 19d selected exhibited...

Direct and site-selective O-arylation of carbohydrates has been a challenge in synthesis. Herein we report method based on copper-catalyzed to address this challenge. Proper choice the ancillary ligand copper is critical for efficiency site selectivity transformation. This features mild conditions, tolerates various functional groups, demonstrates broad substrate scope.

Organocatalysts containing primary-secondary diamines based on bispidine have been developed to catalyze the asymmetric Michael addition of ketones alkylidene malonates and nitroalkenes. The corresponding products were obtained in high yields (up 99%) with diastereoselectivities 99:1) enantioselectivities 97% ee) under mild conditions using either environmentally benign water as solvent or no solvent.

Abstract A highly diastereoselective and enantioselective Michael addition of cyclohexanone, acetone other ketones to nitroolefins was developed by the use an amine organocatalyst based on bispidine. Additionally, a theoretical study transition structures revealed that this bispidine‐based primary‐secondary catalyst could serve through enamine intermediate H‐bond interaction, which important for reactivity selectivity reaction.

Abstract We have found that readily available N ‐alkyl hydroxylamines are effective reagents for the amination of organoboronic acids in presence trichloroacetonitrile. This reaction proceeds rapidly at room temperature and absence added metal or base, it tolerates a remarkable range functional groups, can be used late‐stage assembly two complex units.

The metal catalysts encapsulated in nanomaterials have recently been applied successfully bioorthogonal chemistry for intracellular generation of bioactive compounds. However, the nanomaterial-involved catalysis is intrinsically different from that solution or extracellular fluid. Except reactivity catalyst itself, supporting material's morphology and biocompatibility are essential factors building optimal nanocatalysts. Herein, we present a new nanocopper-doped cross-linked lipoic acid...

We herein report the identification, structural optimization, and structure–activity relationship of thieno[2,3-d]pyrimidine derivatives as a novel kind selective vascular endothelial growth factor receptor 3 (VEGFR3) inhibitors. N-(4-Chloro-3-(trifluoromethyl)phenyl)-4-(6-(4-(4-methylpiperazin-1-yl)phenyl)thieno[2,3-d]pyrimidin-4-yl)piperazine-1-carboxamide (38k) was most potent VEGFR3 inhibitor (IC50 = 110.4 nM) among developed compounds. Compared with VEGFR1 VEGFR2, approximately 100...

A new efficient Pd-catalyzed cascade Heck-Saegusa protocol for the synthesis of synthetically useful alpha,beta-unsaturated aldehydes in high yields from readily available aryl iodides and allyl alcohol has been developed.

Achieving precise restoration of tooth function and personalized natural esthetics has always been a significant challenge in direct restorative dentistry. The traditional techniques are limited by the subjective operations dentists, resulting high technical sensitivity, long operation time, unpredictable results, making it difficult to meet patients' demands for outcomes. An innovative flowable resin injection technique was introduced this study. By combining digital design with guides,...

Abstract This paper describes the successful development of hetero‐Diels–Alder (HDA) reaction Brassard diene with aldehydes in presence a series titanium( IV ) tridentate Schiff‐base complexes under mild conditions. The influence substituent chiral ligands on enantioselectivities was studied. It found that ligand L13 is highly enantioselective for Ti‐catalyzed HDA reaction, affording 6‐substituted 4‐ethoxy‐5,6‐dihydropyran‐2‐one up to 99 % ee . mechanism between and benzaldehyde (Schiff...

Abstract A modular sugar‐based pyrrolidine ( 3 ) was prepared and found to be a highly enantioselective organocatalyst for the asymmetric Michael addition of ketones nitrostyrenes. In presence 10 mol% , unit anchored natural D ‐glucose backbone through click chemistry, additions nitrostyrenes proceeded smoothly generate corresponding adducts in good yields (up 98%), high enantioselectivities >99% ee excellent diastereoselectivities >99:1 dr under solvent‐free reaction conditions.

A chitosan aerogel catalyzed asymmetric aldol reaction of ketones with isatins in the presence water is described. This protocol was found to be environmentally benign, because it proceeds smoothly and corresponding products were obtained excellent yields good enantioselectivities.