A direct asymmetric addition of a (2-thienyl)aluminum reagent to ketones catalyzed by a titanium catalyst of (S)-BINOL to afford chiral tertiary 2-thienyl alcohols is reported. The catalytic system works excellently for aromatic ketones and for 1-acetylcyclohexene, furnishing products in excellent enantioselectivities of up to 97% ee. However, the additions to dialkyl ketones afford products in low enantioselectivities of 8-17% ee. Importantly, a concise 3-step synthesis of (S)-tiemonium iodide with an 84% yield is demonstrated.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/ol901193q | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Merging SOMO activation with transition metal catalysis: Deoxygenative functionalization of amides to β-aryl amines.
Sci Adv
January 2025
State Key Laboratory of Organometallic Chemistry and Shanghai Hongkong Joint Laboratory in Chemical Synthesis, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032 (China).
Singly occupied molecular orbital (SOMO) activation of in situ generated enamines has achieved great success in (asymmetric) α-functionalization of carbonyl compounds. However, examples on the use of this activation mode in the transformations of other functional groups are rare, and the combination of SOMO activation with transition metal catalysis is still less explored. In the area of deoxygenative functionalization of amides, intermediates such as iminium ions and enamines were often generated in situ to result in the formation of α-functionalized amines.
View Article and Find Full Text PDFBinding-Site Directed Selection and Large-Scale Click-Synthesis of a Coagulation Factor XIa-Inhibiting Circular DNA Aptamer.
Chemistry
January 2025
Hefei University of Technology, School of Food and Biological Engineering, Tunxi Road 193, Hefei, CHINA.
Factor XIa (FXIa) is a plasma protease that plays a crucial role in the intrinsic pathway of blood coagulation, making it a promising target for antithrombotic therapy. Circular DNA aptamers, with their dramatically enhanced biological and structural stability, hold great potential as new-generation DNA-based anticoagulants. However, the functional selection and large-scale synthesis of them remains a substantial challenge.
View Article and Find Full Text PDFSuperior colliculus controls the activity of the substantia nigra pars compacta and ventral tegmental area in an asymmetrical manner.
J Neurosci
January 2025
Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University, 9 Gronostajowa street, 30-387 Kraków, Poland.
Dopaminergic (DA) neurons of the substantia nigra pars compacta (SNc) and ventral tegmental area (VTA) play a crucial role in controlling animals' orienting and approach behaviors toward relevant environmental stimuli. The ventral midbrain receives sensory input from the superior colliculus (SC), a tectal region processing information from contralateral receptive fields of various modalities. Given the significant influence of dopamine release imbalance in the left and right striatum on animals' movement direction, our study aimed to investigate the lateralization of the connection between the lateral SC and the midbrain DA system in male rats.
View Article and Find Full Text PDFKinetics During the Tuck Jump Assessment and Biomechanical Deficits in Female Athletes 12 Months After ACLR Surgery.
Am J Sports Med
January 2025
Youth Physical Development Centre, Cardiff School of Sport and Health Sciences, Cardiff Metropolitan University, Cardiff, UK.
Background: Residual interlimb deficits after anterior cruciate ligament reconstruction (ACLR) can lead to functional maladaptation and increase the risk of reinjury. The tuck jump assessment (TJA) may offer a more effective evaluation of ACLR status as compared with traditional tasks owing to increased risk of altered landing mechanics, asymmetrical landing, and increased knee valgus attributed to the cyclical nature of the task. However, it remains unclear whether altered TJA kinetics resolve over time or persist through return-to-play phases of rehabilitation.
View Article and Find Full Text PDFTaming Highly Enolizable Aldehydes via Enzyme Catalysis for Enantiocomplementary Construction of β-Hydroxyphosphonates.
J Am Chem Soc
January 2025
State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China.
Taming highly enolizable aldehydes for catalytic asymmetric C-C coupling with nucleophiles remains an elusive challenge compared to widely explored simple alkyl or aryl aldehydes. Herein, we use ThDP-dependent enzymes to realize the direct C-C coupling of highly enolizable 2-phosphonate aldehydes with in situ-generated dynamically reversible nucleophiles (acyl anions). Unlike NHC-mediated reactions that yield complex mixtures of multiple adducts, our enzymatic process selectively produces biologically active β-hydroxy phosphonates with high yields (up to 95%) and excellent enantioselectivities (up to 99% ee).
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!