Results 81 to 90 of about 29,422 (294)

Catalytic Functionalization of Unactivated π‐Bonds Enabled by Bidentate Directing Auxiliaries

Angewandte Chemie, EarlyView.
This review explores how bidentate directing auxiliaries have advanced transition‐metal catalysis for unactivated alkene/alkyne functionalization. By leveraging chelated intermediates, bidentate directing auxiliaries enable precise hydrofunctionalization, difunctionalization, and C─H activation of π‐bonds with unique selectivity and reactivity.
Seunghyeon Cho, Al Vicente Riano D. Lisboa, Juntao Sun, Taeho Kang, Keary M. Engle   +4 more
wiley   +2 more sources

Heterogeneous Catalysts in Pictet-Spengler-Type Reactions

Journal of Chemistry, 2013
Several solid catalysts were evaluated as an alternative for 1,2,3,4-tetrahydroisoquinoline synthesis by means of the Pictet-Spengler reaction. The reaction catalysed by a mixed oxide (Mg and Al) led to the best yield and good regioselectivity; using an ...
Rodolfo Quevedo, Camilo Perdomo, Sonia Moreno   +2 more
doaj   +1 more source

Atroposelective Access to π‐Conjugated 1,2‐Azaborepines Enabled by Palladium‐Catalyzed Cyclization of N‐Heterobiaryls with Alkynylboronates

Advanced Science, EarlyView.
We report a palladium‐catalyzed atroposelective cyclization of N‐heterobiaryl triflates with alkynyl boronates to access seven‐membered 1,2‐BN‐bridged biaryls with high yields and excellent enantioselectivity via a cascade DyKAT, cis‐carbopalladation, and 1,2‐migration, which expands the toolbox for axially chiral π‐conjugated boron compounds and opens
Fengya He, Zhen Wang, Haoyu Guo, Shuguang Chen, Xu Zhang, Yongjia Shang, Hui Wang   +6 more
wiley   +1 more source

Alkyne Hydroacylation: Switching Regioselectivity by Tandem Ruthenium Catalysis [PDF]

, 2015
By using tandem Ru-catalysis, internal alkynes can be coupled with aldehydes for the synthesis of β,γ-unsaturated ketones. The catalyst promotes alkyne transformations with high regioselectivity, with examples that include the differentiation of a methyl
Vy M. Dong (1311219), Qing-An Chen (1311222), Faben A. Cruz (1639693), Cruz, Faben A, Dong, Vy M, Chen, Qing-An   +5 more
core   +1 more source

Tailoring Regioselectivity‐Controlled UDP‐Glycosyltransferase for Bidirectional Glycosylation of Tyrosol via Free Energy‐Driven Pocket Reshaping and Tunnel Engineering

Advanced Science
UDP‐glycosyltransferases (UGTs) are pivotal biocatalysts for synthesizing pharmaceutically valuable active components; however, their application is frequently constrained by poor regioselectivity and suboptimal catalytic efficiency.
Ziyu Zhang, Jingyi Chen, Zuozhi Liang, Wenming Shao, Zhen Gao, Bin Wu, Bingfang He, Gerhard Schenk   +7 more
doaj   +1 more source

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

Bulletin 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, Alfhons Daniel Sirampun, Rino Rakhmata Mukti, Didin Mujahidin   +3 more
doaj   +1 more source

A Lipid‐Conjugation Strategy for Intracellular Reactive Oxygen Species Control in Hepatic Cells

Angewandte Chemie, EarlyView.
A lipid conjugation strategy anchors a manganese Salen complex within phospholipid membranes, yielding stable, catalytically active liposomes. These lipid–metal assemblies efficiently degrade reactive oxygen species (ROS) and enable intracellular redox control in steatotic HepaRG cells, offering a precise route to biomimetic antioxidant design ...
Olav Vestrheim, Huichao Zhao, Anders Bodholt Nielsen, Nino Wili, Niels Chr. Nielsen, Joseph A. Lyons, Rajeshwar Prosad Mookerjee, Brigitte Städler   +7 more
wiley   +2 more sources

Iron‐Photocatalyzed C(sp3)–H Phosphonylation of Alkanes

Angewandte Chemie, EarlyView.
Alkyl phosphonates are valuable motifs that can be prepared by phosphonylations of various common functional groups. However, direct phosphonylations of C(sp3)–H bonds are limited to activated positions. Herein, we report an iron‐photocatalyzed phosphonylation of unactivated C(sp3)–H bonds using a novel phosphite radical trap, which is equipped with an
Ya Dong, Wangyujing Han, Hanwen Zhang, Santosh K. Pagire, Harry Meats, Adam Noble, Varinder K. Aggarwal   +6 more
wiley   +2 more sources

Regioselective Hydroformylation of Allylic Alcohols [PDF]

Organic Letters, 2011
A highly regioselective hydroformylation of allylic alcohols is reported toward the synthesis of β-hydroxy-acid and aldehyde products. The selectivity is achieved through the use of a ligand that reversibly binds to alcohols in situ, allowing for a directed hydroformylation to occur.
Thomas E, Lightburn, Omar A, De Paolis, Ka H, Cheng, Kian L, Tan   +3 more
openaire   +2 more sources

Automated Dynamic Flow Experimentation for Rapid Kinetic Fitting of Transition Metal Catalysis

Angewandte Chemie, EarlyView.
We have developed an automated dynamic flow experimentation platform to automatically fit and identify the most accurate kinetic model from a generated set of candidates. Three transition metal‐catalyzed transformations were performed using this workflow.
Florian L. Wagner, Klara Silber, Tobias A. Doliner, C. Oliver Kappe   +3 more
wiley   +2 more sources