Coordination-Induced Weakening of a C(sp³)–H Bond: Homolytic and Heterolytic Bond Strength of a CH–Ni Agostic Interaction

The scission of a C­(sp3)–H bond to form a new metal–alkyl bond is a fundamental step in coordination chemistry and catalysis. However, the extent of C–H bond weakening when this moiety interacts with a transition metal is poorly understood and quantifying this phenomenon could provide insights into designing more efficient C–H functionalization catalysts. We present a nickel complex with a robust adamantyl reporter ligand that enables the measurement of C–H acidity (pKa) and bond dissociation free energy (BDFE) for a C­(sp3)–H agostic interaction, showing a decrease in pKa by dozens of orders of magnitude and BDFE decrease of about 30 kcal/mol upon coordination. X-ray crystallographic data is provided for all molecules, including a distorted square planar NiIII metalloradical and “doubly agostic” NiII(κ2-CH2) complex

First reported case of ANCA-associated vasculitis induced by oxaliplatin, capecitabine, and trastuzumab

A 68-year-old male, who was undergoing XELOX plus trastuzumab therapy for gastric cancer, developed proteinuria, hematuria, and progressive increase in creatinine after 3 months. Subsequently, the patient also experienced hemoptysis, nasal bleeding. Chest CT examination shown pulmonary hemorrhage. The MRI of the nasopharynx ruled out nasopharyngeal cancer recurrence. The MPO and PR3 were elevated, and renal biopsy confirmed ANCA-related vasculitis, which affected the lungs, kidneys, and nasopharynx. Based on the review of the patient’’s medical history and medication, it is believed that ANCA-related vasculitis was caused by XELOX plus trastuzumab chemotherapy, but it is difficult to confirm which specific drug caused it. After stopping XELOX plus trastuzumab chemotherapy, glucocorticoids and cyclophosphamide was given, the patient’’s pulmonary hemorrhage and nasal bleeding stopped, and the lung lesions were absorbed. The renal function also improved. The patient later experienced pulmonary infection again, and tNGS indicated Legionella pneumophila and pulmonary tuberculosis infection. Despite anti-infection treatment, steroid dose was rapidly reduced. Ultimately, the patient gave up on treatment and eventually died.</p

Coordination-Induced Weakening of a C(sp³)–H Bond: Homolytic and Heterolytic Bond Strength of a CH–Ni Agostic Interaction

The scission of a C­(sp3)–H bond to form a new metal–alkyl bond is a fundamental step in coordination chemistry and catalysis. However, the extent of C–H bond weakening when this moiety interacts with a transition metal is poorly understood and quantifying this phenomenon could provide insights into designing more efficient C–H functionalization catalysts. We present a nickel complex with a robust adamantyl reporter ligand that enables the measurement of C–H acidity (pKa) and bond dissociation free energy (BDFE) for a C­(sp3)–H agostic interaction, showing a decrease in pKa by dozens of orders of magnitude and BDFE decrease of about 30 kcal/mol upon coordination. X-ray crystallographic data is provided for all molecules, including a distorted square planar NiIII metalloradical and “doubly agostic” NiII(κ2-CH2) complex