The Pd(0) complexes [(NHC)PdL(n)] (NHC=N-heterocyclic carbene ligand; L=styrene for n=2 or PR(3) for n=1) efficiently catalyse olefin cyclopropanation by using ethyl diazoacetate (EDA) as the carbene source with activities that improve on previously described catalytic systems based on this metal. Mechanistic studies have shown that all of these catalyst precursors deliver the same catalytic species in solution, that is, [(IPr)Pd(sty)], a 14e(-) unsaturated intermediate that further reacts with EDA to afford [(IPr)Pd(=CHCO(2)Et)(sty)], from which the cyclopropane is formed.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1002/chem.201102900 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
DNA Methylation Is Crucial for 1-Methylcyclopropene Delaying Postharvest Ripening and Senescence of Tomato Fruit.
Int J Mol Sci
December 2024
Key Laboratory of Food Nutrition and Functional Food of Hainan Province, School of Food Science and Engineering, Hainan University, Haikou 570228, China.
DNA methylation is an epigenetic modification process that can alter the functionality of a genome. It has been reported to be a key regulator of fruit ripening. In this study, the DNA methylation changes of CpG islands of ethylene signaling genes regulated by 1-methylcyclopropene (1-MCP) during ripening and senescence of tomato fruit were detected.
View Article and Find Full Text PDFSynthetic studies towards naturally occurring sesquiterpene capillosanane V: construction of a fully functionalized cycloheptane core through an intramolecular Reformatsky reaction.
Org Biomol Chem
January 2025
Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur, 721302, India.
We herein disclose the synthesis of a bicyclo [5,1,0]-octane ring system consisting of a cycloheptane core fused with a cyclopropane unit of naturally occurring sesquiterpene capillosanane V. Initially, an unsuccessful RCM reaction of a properly functionalized bis-olefinic precursor was attempted. Finally, an intramolecular Reformatsky reaction was employed to construct the cycloheptane core present in the target structure.
View Article and Find Full Text PDFMachine-Learning-Aided Engineering Hemoglobin as Carbene Transferase for Catalyzing Enantioselective Olefin Cyclopropanation.
JACS Au
December 2024
Key Laboratory of Molecular Enzymology and Engineering of Ministry of Education, School of Life Sciences, Jilin University, Changchun 130023, P. R. China.
In this study, we developed a machine-learning-aided protein design strategy for engineering hemoglobin (VHb) as carbene transferase. A Natural Language Processing (NLP) model was used for the first time to construct an algorithm (EESP, enzyme enantioselectivity score predictor) and predict the enantioselectivity of VHb. We identified critical amino acid residue sites by molecular docking and established a simplified mutation library by site-saturated mutagenesis.
View Article and Find Full Text PDFGlycosyl Radical-Based Synthesis of -Alkyl Glycosides Bearing a Cyclopropane via a Deoxygenative Giese Addition-Reduction-Cyclization Cascade.
Org Lett
January 2025
National Engineering Research Center for Carbohydrate Synthesis, Jiangxi Normal University, Nanchang 330022, China.
We have developed a glycosyl radical-based synthesis of -alkyl glycosides through a deoxygenative Giese addition-reduction-cyclization cascade, in which readily available 1-hydroxy carbohydrates serve as precursors for glycosyl radicals and aryl alkenes function as radical acceptors. This reaction not only provides an effective method for accessing a previously underexplored class of functionalized cyclopropanes but also enhances the application of Giese addition in the synthesis of -alkyl glycosides by derivatizing the radical intermediate generated through polar cyclization to yield a cyclopropane.
View Article and Find Full Text PDFA General Platform for Copper-Catalyzed Atom Transfer Radical Addition with Electron-Deficient Olefins.
Org Lett
January 2025
Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States.
We disclose a broad platform for copper-catalyzed atom transfer radical addition (ATRA) of electron-deficient olefins. Catalytic Cu(dtbbpy)(OTf) enables radical addition of electron-deficient alkyl halides to acrylates, acrylamides, and vinyl sulfones in fair to excellent yields. The resultant ATRA products can be used in a variety of telescoped reactions, including substitution with basic amine nucleophiles to afford α-amino esters.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!