A practical and highly stereoselective iron-catalyzed cross-coupling reaction of stereodefined enol carbamates and Grignard reagents to yield tri- and tetrasubstituted acrylates is reported. A facile method for the stereoselective generation of these enol carbamates has also been developed.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1002/anie.201601899 | DOI Listing |
Synlett
November 2023
UT Southwestern Medical Center, Department of Biochemistry, 5323 Harry Hines Blvd., Dallas Texas 75390-9038.
Rh-catalyzed asymmetric hydroboration of enol carbamates yields α-boryl carbamates in good enantioselectivity. The enol carbamate starting materials can be prepared with moderate selectivity using a modified Juila olefination and used as an mixture, taking advantage of the faster reactivity of the major isomer in the directed hydroboration. Optically active α-boryl carbamates participate in a Matteson-type homologation with Grignard reagents in which the O-carbamate is substituted with high conservation of optical activity to provide enantioenriched secondary boronic esters.
View Article and Find Full Text PDFMolecules
May 2024
Laboratorio de Bioquímica Genética, Instituto Nacional de Pediatría, Secretaría de Salud, Mexico City 04530, Mexico.
Metronidazole (MTZ) is the most common drug used against () infections; however, treatment failures and high rates of recurrence of trichomoniasis have been reported, suggesting the presence of resistance in to MTZ. Therefore, research into new therapeutic options against infections has become increasingly urgent. This study investigated the trichomonacidal activity of a series of five imidazole carbamate compounds (AGR-1, AGR-2, AGR-3, AGR-4, and AGR-5) through in vitro susceptibility assays to determine the IC value of each compound.
View Article and Find Full Text PDFChem Sci
November 2023
Department of Chemistry, City University of Hong Kong Tat Chee Avenue Kowloon Hong Kong P. R. China
Photosensitisers for photoimmunotherapy with high spatiotemporal controllability are rare. In this work, we designed rhenium(i) polypyridine complexes modified with a tetrazine unit a bioorthogonally activatable carbamate linker as bioorthogonally dissociative photosensitisers for the controlled induction of immunogenic cell death (ICD). The complexes displayed increased emission intensities and singlet oxygen (O) generation efficiencies upon reaction with -cyclooct-4-enol (TCO-OH) due to the separation of the quenching tetrazine unit from the rhenium(i) polypyridine core.
View Article and Find Full Text PDFPhytochemistry
August 2023
School of Life Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, Sichuan, PR China; Southwest Jiaotong University, Affiliated Hospital, The Third People's Hospital of Chengdu, Chengdu, 610000, Sichuan, PR China. Electronic address:
A chemical investigation of the EtOAc extract of the endophytic fungus Penicillium herquei led to the isolation of nine undescribed oxidized ergosterols, penicisterols A-I (1-9), along with ten known analogs (10-19). Their structures and absolute configurations were elucidated by a combination of spectroscopic data analysis, quantum-chemical electronic circular dichroism (ECD) calculations and comparisons, [Rh(OCOCF)]-induced ECD experiments, DFT-calculated C chemical shifts and DP4+ probability analysis. Compound 1 was a rare example of ergosterol in which the bond between C-8 and C-9 was cleaved to form an enol ether.
View Article and Find Full Text PDFChemistry
August 2022
Department of Organic Chemistry, Stockholm University, Stockholm, 10691, Sweden.
In this paper, we present an unprecedented and general umpolung protocol that allows the functionalization of silyl enol ethers and of 1,3-dicarbonyl compounds with a large range of heteroatom nucleophiles, including carboxylic acids, alcohols, primary and secondary amines, azide, thiols, and also anionic carbamates derived from CO . The scope of the reaction also extends to carbon-based nucleophiles. The reaction relies on the use of 1-bromo-3,3-dimethyl-1,3-dihydro-1λ [d][1,2]iodaoxole, which provides a key α-brominated carbonyl intermediate.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!