Quinoline-derived NNP-manganese complex catalyzed α-alkylation of ketones with primary alcohols.

An air-stable quinoline-derived NNP ligand chelated Mn catalyst was developed for the efficient α-alkylation of ketones with primary alcohols via a hydrogen auto-transfer methodology. The sole by-product formed is water, rendering the protocol atom efficient. A wide range of ketone and alcohol substrates were employed, providing the α-alkylated ketones with isolated yields up to 94%. This system was also efficient for the green synthesis of quinoline derivatives while using (2-aminophenyl)methanol as an alkylating reagent.

Impact of the extent of recurrent laryngeal nerve lymphadenectomy on thoracic esophageal squamous cell carcinoma: a real-world multicentre study.

OBJECTIVES: To determine the impact of recurrent laryngeal nerve (RLN) lymph node (LN) dissection on survival and postoperative complications in patients with oesophageal squamous cell carcinoma (ESCC). METHODS: Patients with cT1-4N0-3M0 thoracic ESCC who underwent oesophagectomy and two-field lymphadenectomy from three institutions were included. The entire cohort was divided into three groups that underwent the total two-field lymphadenectomy (T-2FL), standard two-field lymphadenectomy (S-2FL) or unilateral RLN-LN dissection plus S-2FL (U-2FL) based on the extent of RLN-LN dissection. Subgroup analyses were also performed and were stratified by treatment modality. RESULTS: Both the U-2FL and T-2FL groups had significantly superior outcomes compared with the S-2FL group (overall survival: U-2FL versus S-2FL: P = 0.002; T-2FL versus S-2FL: P < 0.001; recurrence-free survival: U-2FL versus S-2FL: P = 0.01; T-2FL versus S-2FL: P < 0.001). Moreover, no significant differences were observed between U-2FL and T-2FL regarding overall survival (P > 0.05) and recurrence-free survival (P > 0.05), irrespective of administration of neoadjuvant therapy plus oesophagectomy or upfront oesophagectomy. Additionally, the extent of RLN-LN dissection was not an independent predictor of stage migration (P = 0.14) but was for postoperative nodal upstaging (P = 0.02). Notably, S-2FL brought significantly lowered risk in postoperative complications, especially for RLN palsy, when compared with T-2FL (P = 0.002) but not U-2FL (P = 0.72). CONCLUSIONS: Adequacy of RLN-LN dissection is an important prognosticator for improved overall survival and recurrence-free survival in patients with thoracic ESCC. U-2FL may serve as an alternative to T-2FL in selected populations.

Synthesis of Axially Chiral Biaryls via Enantioselective Ullmann Coupling of ortho-Chlorinated Aryl Aldehydes Enabled by a Chiral 2,2'-Bipyridine Ligand.

The first nickel-catalyzed highly enantioselective reductive Ullmann coupling of ortho-chlorinated aryl aldehyde was achieved under mild reaction conditions with a chiral 2,2'-bipyridine ligand (+)-DTB-SBpy, thus providing axially chiral biphenyl or binaphthyl dials with up to 99 % yield and 99.5:0.5 er. The versatility of the products as common synthetic intermediates for diverse axially chiral ligands, catalysts, and functional molecules was demonstrated by short-step transformations. This protocol also allowed the concise and highly enantioselective formal total synthesis of biologically active natural products (+)-kotanin, (-)-isoschizandrin and (+)-gossypol.

Design and Synthesis of Tunable Chiral 2,2'-Bipyridine Ligands: Application to the Enantioselective Nickel-Catalyzed Reductive Arylation of Aldehydes.

A new class of chiral 2,2'-bipyridine ligands, SBpy, featuring minimized short-range steric hindrance and structural tunability was rationally designed and developed, and the effectiveness was demonstrated in the first highly enantioselective Ni-catalyzed addition of aryl halides to aldehydes. In comparison with known approaches using preformed aryl metallic reagents, this reaction is more step-economical and functional group tolerant. The reaction mechanism and a model of stereocontrol were proposed based on experimental and computational results.

Extracapsular lymph node involvement is a robust survival predictor in esophageal cancer patients: A pooled analysis.

BACKGROUND: Although extracapsular lymph node involvement (EC-LNI) has been proposed to be incorporated into the staging system of esophageal cancer, the prognostic value of EC-LNI remains controversial with conflicting data available, especially in the era of neoadjuvant therapy. METHODS: An electronic literature search was undertaken using four public databases. Studies investigating the effects of EC-LNI on survival were included. In addition to analysis of the entire cohort, subset analyses were also performed to assess the impact of EC-LNI on patients receiving different treatment modalities. RESULTS: A total of 20 studies were included in this meta-analysis. Pooling 13 studies on overall survival (OS), we observed that presence of EC-LNI was associated with significantly worse OS (HR = 2.09, 95%CI: 1.63-2.68; p < 0.01). Nine studies describing disease-free survival (DFS) included, the pooled data revealed that presence of EC-LNI was associated with significantly worse DFS (HR = 1.89, 95%CI: 1.63-2.20; p < 0.001). Subset analyses of patients receiving neoadjuvant therapy demonstrated a survival disadvantage of EC-LNI on OS (HR = 1.928, 95%CI: 1.196-3.107; p = 0.007) and DFS (HR = 1.985, 95%CI: 1.585-2.487; p < 0.001). Similar result was also seen in patients receiving primary surgery (OS: HR = 2.219, 95%CI: 1.720-2.864; p < 0.001; DFS: HR = 1.659, 95%CI: 1.285-2.141; p < 0.001). CONCLUSION: EC-LNI is a strong prognostic predictor of inferior survival in patients with esophageal cancer irrespective of treatment modality. The currently pooled evidence indicates that EC-LNI has great potential to be incorporated into the future staging system.

A new air-stable Si,S-chelating ligand for Ir-catalyzed directed ortho C-H borylation.

A new air-stable Si,S-chelating ligand has been developed and used in an iridium-catalyzed ortho C-H borylation reaction with a broad substrate scope. This study provides the first example of using a sulfur-containing ligand in the catalytic C-H borylation process. It provides a rapid, efficient, and economical method for the preparation of organoboron compounds.

Recent Progress in Continuous-Flow Hydrogenation.

To achieve a safe, efficient, and sustainable (even fully automated) production for the continuous-flow hydrogenation reactions, which is among the most often used reactions in chemical synthesis, new catalyst types and immobilization methods as well as flow reactors and technologies have been developed over the last years; in addition, these approaches have been combined with new and transformational technologies in other fields such as artificial intelligence. Thus, attention from academic and industry practitioners has increasingly focused on improving the performance of hydrogenation in flow mode by reducing the reaction times, increasing selectivities, and achieve safe operation. This Minireview aims to summarize the most recent research results on this topic with focus on the advantages, current limitations, and future directions of flow chemistry.