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The significance of stereoselective C−H bond functionalization thrives on its direct application potential to pharmaceuticals or complex chiral molecule synthesis. Complication arises when there are multiple stereogenic elements such as a center and an axis of chirality to control. Over the years cooperative assistance of multiple chiral ligands has been applied to control only chiral centers. In this work, we harness the essence of cooperative ligand approach to control two different stereogenic elements in the same molecule by atroposelective allylation to synthesize axially chiral biaryls from its racemic precursor. The crucial roles played by chiral phosphoric acid and chiral amino acid ligand in concert helped us to obtain one major stereoisomer out of four distinct possibilities. [ABSTRACT FROM AUTHOR]

2-Pyridone ligand-facilitated palladium-catalyzed direct C–H bond functionalization via the transient directing group strategy has become an attractive topic. Here, we report a Pd-catalyzed direct β-C(sp3)–H arylation reaction of tertiary aliphatic aldehydes by using an α-amino acid as a transient directing group in combination with a 2-pyridone ligand. [ABSTRACT FROM AUTHOR]

Increasing evidence has shown that circular RNAs (circRNAs) interact with RNA‐binding proteins (RBPs) and promote cancer progression. However, the function and mechanism of the circRNA/RBP complex in esophageal squamous cell carcinoma (ESCC) are still largely unknown. Herein, we first characterized a novel oncogenic circRNA, circ‐FIRRE, by RNA sequencing (Ribo‐free) profiling of ESCC samples. Furthermore, we observed marked circ‐FIRRE overexpression in ESCC patients with high TNM stage and poor overall survival. Mechanistic studies indicated that circ‐FIRRE, as a platform, interacts with the heterogeneous nuclear ribonucleoprotein C (HNRNPC) protein to stabilize GLI2 mRNA by directly binding to its 3'‐UTR in the cytoplasm, thereby resulting in elevated GLI2 protein expression and subsequent transcription of its target genes MYC, CCNE1, and CCNE2, ultimately contributing to ESCC progression. Moreover, HNRNPC overexpression in circ‐FIRRE knockdown cells notably abolished circ‐FIRRE knockdown‐mediated Hedgehog pathway inhibition and ESCC progression impairment in vitro and in vivo. Clinical specimen results showed that circ‐FIRRE and HNRNPC expression was positively correlated with GLI2 expression, which reveals the clear significance of the circ‐FIRRE/HNRNPC‐GLI2 axis in ESCC. In summary, our results indicate that circ‐FIRRE could serve as a valuable biomarker and potential therapeutic target for ESCC and highlight a novel mechanism of the circ‐FIRRE/HNRNPC complex in ESCC progression regulation. [ABSTRACT FROM AUTHOR]