Results 51 to 60 of about 15,429 (247)

A Straightforward Selective Acylation of Phenols over ZSM-5 towards Making Paracetamol Precursors

open access: yesBulletin of Chemical Reaction Engineering & Catalysis, 2018
Commercially available ZSM-5 was minimally treated as the catalyst to selectively acylate phenols. The ZSM-5 was simply immersed in ammonium nitrate in order to fill the pores with Brönsted acid to concentrate the catalytic reactions inside the pores ...
Robby Roswanda   +3 more
doaj   +1 more source

Exploring the Potential of Cytochrome P450 CYP109B1 Catalyzed Regio—and Stereoselective Steroid Hydroxylation

open access: yesFrontiers in Chemistry, 2021
Cytochrome P450 enzyme CYP109B1 is a versatile biocatalyst exhibiting hydroxylation activities toward various substrates. However, the regio- and stereoselective steroid hydroxylation by CYP109B1 is far less explored.
Xiaodong Zhang   +6 more
doaj   +1 more source

Computation‐Guided Tunnel Engineering Enhances O2 Transport and H2O2 Resistance of Fe(II)/α‐Ketoglutarate‐Dependent Dioxygenases

open access: yesAdvanced Science, EarlyView.
This study presents a computational tunnel engineering strategy in Fe(II)/α‐ketoglutarate‐dependent dioxygenases (αKGDs) to enhance oxygen (O2) transport, an essential molecule for αKGDs, and limit hydrogen peroxide (H2O2) entry, an inhibitor from the αKG supply system.
Huan Liu   +10 more
wiley   +1 more source

Palladium‐Catalyzed Annulations of an Anti‐Bredt Olefin

open access: yesAngewandte Chemie, EarlyView.
We report metal‐catalyzed trappings of a [2.2.1]‐bridged bicyclic anti‐Bredt olefin (ABO). The methodology yields unusual heterocyclic products and is expected to prompt the further development of unconventional reactions, including metal‐catalyzed processes of ABOs and other strained olefins. ABSTRACT A famous class of alkene‐containing compounds that
Zach G. Walters   +3 more
wiley   +2 more sources

Pd‐Catalyzed Asymmetric Dearomative Heck/Tsuji‐Trost Difunctionalization of Naphthalenes

open access: yesAdvanced Science, EarlyView.
We have developed a palladium‐catalyzed asymmetric dearomative Heck/Tsuji‐Trost 1,4‐difunctionalization reaction of naphthalenes, affording 4‐aminospirocyclohexene oxindole products bearing two remote chiral centers. Through the effect of the newly designed chiral sulfinamide phosphine ligand with large steric hindrance, side reactions are inhibited ...
Long‐Ling Ma   +3 more
wiley   +1 more source

Strain‐Release Pentafluorosulfanylation of Carbonyl‐Containing Disubstituted Bicyclobutanes: A Fortuitous Path to SF5‐Containing Oxa[2.1.1]bicyclohexanes

open access: yesAngewandte Chemie, EarlyView.
A regio‐ and diastereoselective method for strain‐release pentafluorosulfanylation of carbonyl‐containing 1,3‐disubstituted [1.1.0]bicyclobutanes (BCBs) was developed that led to several fortuitous discoveries. For instance, the resultant SF5‐cyclobutanes (SF5‐CBs) exhibit close SF5⋯C═X contacts (X = C, N, O) and provide synthetic access to a new class
Alexander M. Stephens   +9 more
wiley   +2 more sources

Design and Engineering of an Artificial Bifunctional N‐Deacetylase/N‐Sulfotransferase for the Biosynthesis of N‐Sulfated Heparosan

open access: yesAdvanced Science, EarlyView.
An artificial bifunctional N‐deacetylase/N‐sulfotransferase was engineered in Escherichia coli by combining screened N‐deacetylases with an NST domain. The integrated engineering strategy improved enzyme performance. The optimized enzyme efficiently converted heparosan into N‐sulfated heparosan, addressing a key bottleneck in microbial heparin ...
Xintong Xi   +8 more
wiley   +1 more source

Iridium‐Catalyzed Ionic Hydrogenation of Multi‐Aza Heterocycles

open access: yesAngewandte Chemie, EarlyView.
Saturated nitrogen‐containing heterocycles are ubiquitous in bioactive molecules and are thus attractive synthetic targets. A readily accessible cyclometalated iridium(III) complex reduces 14 different aromatic aza heterocycles to (partially)saturated multi aza‐heterocycles enlarging accessible chemical space while displaying high tolerance toward ...
Arthur Despois, Nicolai Cramer
wiley   +2 more sources

The regioselective aminohydroxylation of allylic carbamates

open access: yesChemical Communications, 2001
The synthesis and aminohydroxylation of a series of acyclic allylic carbamates is described: the formation of a putative O=Os=NR linkage between the transition metal and substrate is proposed to account for the high levels of regioselectivity that were observed; proof of the structure of one of the aminohydroxylation products was obtained through X-ray
Donohoe, T   +3 more
openaire   +2 more sources

A Supramolecular Thermal Switch for Precision Pyroptosis via Host−Guest Recognition and Electrostatic Interactions

open access: yesAdvanced Science, EarlyView.
A supramolecular pyroptotic thermal switch encapsulates I3− within β‐cyclodextrin (β‐CD) and undergoes CaCO3 mineralization. Upon lysosomal acidification, CaCO3 is degraded, releasing Ca2+ and I3−. Concurrently, BODIPY activation converts I3− into I2, inducing oxidative stress and Ca2+ overload, which together trigger caspase‐3/GSDME‐mediated ...
Dan Wu   +8 more
wiley   +1 more source

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