ABSTRACT
Herein, a palladium-catalyzed regioselective alkynylation, esterification, and amination of allylic gem-difluorides via C-F bond activation/transmetallation/ß-C elimination or nucleophilic attack has been achieved. This innovative protocol showcases an extensive substrate range and operates efficiently under mild reaction conditions, resulting in high product yields and Z-selectivity. Particularly noteworthy is its exceptional tolerance towards a wide array of functional groups. This developed methodology provides effective and convenient routes to access a diverse array of essential fluorinated enynes, esters and amines.
ABSTRACT
A novel class of alkyne-tethered amides facilitates an unprecedented photoinduced palladium-catalyzed radical relay formal [5 + 2] reaction. This innovative strategy allows for the rapid construction of diverse fused benzoazepine structures, yielding structurally novel and compelling compounds. With a broad substrate scope and excellent functional group tolerance, the methodology synthesizes biologically active compounds. Notably, the resulting tricyclic benzo[b]azepines offer diversification opportunities through simple transformations. DFT calculations elucidate a seven-membered ring closure mechanism involving the alkenyl radical and Pd(I) rebound alongside a concerted metalation-deprotonation (CMD) process.
ABSTRACT
Significant advancements in synthesis of monofluoroalkenes via palladium-catalyzed reactions involving allylic gem-difluorides and diverse nucleophiles have been achieved. This method allows regioselective arylation, alkylation, allylation, alkenylation, and hydrogenation of allylic gem-difluorides, yielding high Z-selectivity and favorable product yields under mild conditions. Tolerating various functional groups, these transformations utilize a common Pd-OH intermediate. Additionally, employing triple Pd-catalyzed cross-coupling yields diverse trisubstituted alkenes efficiently.
ABSTRACT
Recent research suggested that cardiac stem cells (CSCs) may have the clinical application for cardiac repair. However, their characteristics and the regulatory mechanisms of their growth and differentiation have not been fully investigated. Vascular endothelial growth factor (VEGF, VEGF-A) is a major regulator of physiological and pathological angiogenesis. But the homing role of VEGF for CSCs is unclear. In this report, CSCs were isolated, purified, and expanded in vitro from rat heart. VEGF, SU5416 (VEGF receptor blocker), and Wortmannin (PI3K/Akt signaling pathway inhibitor) were used for differentiation into vascular endothelial cells (VECs). Real-time qPCR was selected to confirm the role of PI3K/Akt signaling pathway in VECs differentiation from rat CSCs. The result of real-time qPCR demonstrated that PI3K/Akt signaling pathway plays an important role in rat CSCs differentiated into VECs. So, our research provides a theoretical basis and experimental evidence for therapeutic application of rat CSCs to treat cardiac repair.
