A5074246418- Microbial Natural Products and Biosynthesis
- Catalytic C–H Functionalization Methods
- Chemical Synthesis and Analysis
- Radical Photochemical Reactions
- Sulfur-Based Synthesis Techniques
- Oxidative Organic Chemistry Reactions
- Insect and Pesticide Research
- Synthetic Organic Chemistry Methods
- Synthesis and Characterization of Pyrroles
- Fluorine in Organic Chemistry
- Chemical synthesis and alkaloids
- Bamboo properties and applications
- Masonry and Concrete Structural Analysis
- Antimicrobial Resistance in Staphylococcus
- Biological Control of Invasive Species
- Optical Coatings and Gratings
- Wood Treatment and Properties
- Toxin Mechanisms and Immunotoxins
- Metamaterials and Metasurfaces Applications
- Agricultural pest management studies
- Seedling growth and survival studies
- Carbohydrate Chemistry and Synthesis
- Plant Gene Expression Analysis
- Alkaloids: synthesis and pharmacology
- Plant and fungal interactions
Scripps Research Institute
2020-2023
Brigham Young University
2014-2022
Sichuan Agricultural University
2017-2022
Sichuan Academy of Forestry
2020
Zhengzhou University
2020
Iminyl radical cyclizations have emerged as important tools for constructing five- and six-membered nitrogen-containing heterocycles. Both aromatic nonaromatic ring systems are readily accessible from a variety of precursors. This short review focuses on recently discovered iminyl cyclizations. Methods that use heat, transition metals, or oxidants to generate the radicals discussed, protocols employing either UV irradiation visible light. Many these newly developed procedures should be quite...
Microwave-promoted iminyl radical cyclizations can be terminated by trapping with TEMPO, affording functionalized adducts. The use of alkynes as acceptors delivers a range 2-acylpyrroles in good yields. Toxic and hazardous reagents, which are frequently employed reactions, not required. O-phenyl oxime ether substrates constructed single step from readily available ketones.
A next-generation total synthesis of vancomycin aglycon is detailed that was achieved in 17 steps (longest linear sequence, LLS) from the constituent amino acid subunits with kinetically controlled diastereoselective introduction all three elements atropisomerism. In addition to new syntheses seven subunits, highlights approach include a ligand-controlled atroposelective one-pot Miyaura borylation–Suzuki coupling sequence for AB biaryl axis chirality (>20:1 dr), an essentially instantaneous...
As an important vegetable crop of the legume family, cowpea (Vigna unguiculata L.) is grown widely for its tender pod with good taste and nutrition. The purple pods attract more attention mainly eye-catching color health-promoting ingredients. Initially, large quantities two major anthocyanins (delphinidin 3-O-glucoside cyanidin 3-O-glucoside) nine kinds flavonoids (most are quercetin-based flavonol glycosides) were separated identified from by ultra-high performance liquid chromatography...
A new streamlined and scaled divergent total synthesis of pocket-modified vancomycin analogs is detailed that provides a common late-stage intermediate [Ψ[C(═S)NH]Tpg4]vancomycin (LLS = 18 steps, 12% overall yield, >5 g prepared) to access both existing future pocket modifications. Highlights the approach include an atroposelective aglycon (11), one-pot enzymatic glycosylation for direct conversion (12), powerful methods embedded thioamide amidine/aminomethylene Incorporation two peripheral...
A concise synthesis of peptides that contain E- or Z-dehydroisoleucine (ΔIle) residues is reported. The key reaction an unusual anti dehydration β-tert-hydroxy amino acid derivatives mediated by the Martin sulfurane. subsequent tandem Staudinger reduction–O → N acyl transfer process forges amide bond to ΔIle residue with minimal E/Z alkene isomerization. Density functional calculations attribute stereospecific a highly asynchronous E2 process.
O-Phenyloximes tethered to alkenes undergo 5-exo-trig iminyl radical cyclizations upon microwave irradiation. Trapping of the resulting cyclic radicals results in C-C, C-N, C-O, C-S, or C-X bond formation. Allylic sulfides a tandem cyclization-thiyl β-elimination, affording terminal alkenes. The exhibit broad scope, and some cases they are highly diastereoselective. pyrroline adducts versatile intermediates that can be transformed into range different species.
A detailed study of iminyl radical cyclizations O-aryloximes tethered to alkenes is reported. The reactions can be triggered by either microwave irradiation or conventional heating in an oil bath. variety traps employed, enabling C–C, C–N, C–O, C–S, C–X bond formation and producing a diverse array functionalized pyrrolines. Substrates containing allylic sulfide furnish terminal tandem cyclization–thiyl β-elimination pathway. Cyclizations hydroxylated substrates exhibit moderate...
Total synthesis of the anticancer peptide natural product yaku'amide A is reported. Its β-tert-hydroxy amino acids were prepared by regioselective aminohydroxylation involving a chiral mesyloxycarbamate reagent. Stereospecific construction E- and Z-ΔIle residues was accomplished through one-pot reaction featuring anti dehydration, azide reduction, O→N acyl transfer. Alkene isomerization negligible during this process. These methods enabled highly convergent efficient synthetic route to product.
Abstract Total synthesis of the anticancer peptide natural product yaku'amide A is reported. Its β‐ tert ‐hydroxy amino acids were prepared by regioselective aminohydroxylation involving a chiral mesyloxycarbamate reagent. Stereospecific construction E ‐ and Z ‐ΔIle residues was accomplished through one‐pot reaction featuring anti dehydration, azide reduction, O→N acyl transfer. Alkene isomerization negligible during this process. These methods enabled highly convergent efficient synthetic...
Abstract The mild protocol does not require toxic or hazardous reagents and tolerates a variety of functional groups including acid base labile ones.