Results 71 to 80 of about 29,422 (294)

Relative Strength of Common Directing Groups in Palladium-Catalyzed Aromatic C−H Activation

iScience, 2019
Summary: Efficient functionalization of C−H bonds can be achieved using transition metal catalysts, such as Pd(OAc)2. To better control the regioselectivity in these reactions, some functional groups on the substrate may be used as directing groups ...
Anna Tomberg, Michael Éric Muratore, Magnus Jan Johansson, Ina Terstiege, Christian Sköld, Per-Ola Norrby   +5 more
doaj   +1 more source

A Simple and Easily Implemented Method for the Regioselective Introduction of Deuterium into Azolo[1,5-a]pyrimidines Molecules

Molecules, 2023
A method for the technically easy-to-implement synthesis of deuterium-labeled pyrazolo[1,5-a]pyrimidines and 1,2,4-triazolo[1,5-a]pyrimidines have been developed. The regioselectivity of such transformations has been shown.
Gevorg G. Danagulyan, Henrik A. Panosyan, Vache K. Gharibyan, Ani H. Hasratyan   +3 more
doaj   +1 more source

Regioselectivity of H Cluster Oxidation

Journal of the American Chemical Society, 2011
The H(2)-evolving potential of [FeFe] hydrogenases is severely limited by the oxygen sensitivity of this class of enzymes. Recent experimental studies on hydrogenase from C. reinhardtii point to O(2)-induced structural changes in the [Fe(4)S(4)] subsite of the H cluster. Here, we investigate the mechanistic basis of this observation by means of density
Bruska, Marta K., Stiebritz, Martin T., Reiher, Markus   +2 more
openaire   +2 more sources

Heterogeneous Visible‐Light Photocatalysis in Continuous‐Flow: A Synergistic Strategy for Challenging Trifluoromethylation of α, α‐Diaryl Allylic Alcohols via 1,2‐aryl Migration

Advanced Science, EarlyView.
A continuous‐flow photocatalytic strategy is presented for the efficient synthesis of β‐trifluoromethyl ketones under visible light. Using a recyclable solid photocatalyst and an inexpensive CF3 source, the method enables rapid reactions, easy scale‐up, and smooth integration into multistep flow synthesis of bioactive molecules.
Peiwen Liu, Weiping Zhu, Xuhong Qian, Fang Zhao   +3 more
wiley   +1 more source

Asymmetric Iron‐Catalyzed Vicinal C(sp3)─H Diamination of Carboxylic Acids

Angewandte Chemie, EarlyView.
An iron‐catalyzed vicinal α,β‐C(sp3)─H diamination of readily available carboxylic acids furnishes chiral α,β‐diamino acids in a single pot with high regio‐, diastereo‐, and enantioselectivity (up to >20:1 dr and >99% ee). ABSTRACT The direct construction of chiral 1,2‐diamines through the stereoselective functionalization of two vicinal C(sp3)─H bonds
Bing Zhou, Yuan Zheng, Xiulan Xie, Marcel Hemming, Sergei I. Ivlev, Eric Meggers   +5 more
wiley   +2 more sources

Ligand-controlled regiodivergent arylation of aryl(alkyl)alkynes and asymmetric synthesis of axially chiral 9-alkylidene-9,10-dihydroanthracenes

Nature Communications
Transition metal-catalyzed addition of organometallics to aryl(alkyl)alkynes has been well known to proceed with the regioselectivity in forming a carbon–carbon bond at the alkyl-substituted carbon (β-addition).
Chao Sun, Ting Qi, Faiz-Ur Rahman, Tamio Hayashi, Jialin Ming   +4 more
doaj   +1 more source

Semi-rational engineering of an α-L-fucosidase for regioselective synthesis of fucosyl-N-acetylglucosamine disaccharides

Food Chemistry: Molecular Sciences
α-L-Fucosidases are attractive biocatalysts for the production of bioactive fucosylated oligosaccharides, however, poor regioselectivity and activity for transglycosylation have significantly limited their applications.
Peng Liu, Xiaodi Chen, Xueting Cao, Yuying Wang, Yafei Gao, Li Xu, Xukai Jiang, Min Xiao   +7 more
doaj   +1 more source

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

Frontiers 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, Yun Hu, Wei Peng, Chenghua Gao, Qiong Xing, Binju Wang, Aitao Li   +6 more
doaj   +1 more source

Spike‐Embedded Nanocatalysts via Metal‐Directed Carbonization for Highly Efficient and Robust Semi‐Hydrogenation

Advanced Science, EarlyView.
A metal‐directed carbonization strategy transforms hierarchical organic microspheres into spiky carbon catalysts with Pd nanoparticles embedded at the tips. This approach resolves the activity‐stability trade‐off, achieving exceptional poison resistance in semi‐hydrogenations, offering a versatile, scalable platform for designing high‐performance ...
Yintao Li, Yang Sun, Minghang Li, Wenxuan Zhang, Zhengtao Li, Yihao Ni, Yao Zhang, Yong Wang, Samuel S. Veroneau, Pengfei Ji   +9 more
wiley   +1 more source

On the mechanism of the Shapiro reaction: Understanding the regioselectivity

, 2015
A detailed DFT-level mechanism elucidation of the two-step reaction of tosylhydrazones with alkyllithium reagents (the Shapiro reaction) is presented.
Funes-Ardoiz, I. [0000-0002-5843-9660], Sampedro, D. [0000-0003-2772-6453], Losantos, R. [0000-0001-5207-654X]   +2 more
core   +1 more source