RESUMO
Route design and proof of concept synthesis was conducted on a synthetically challenging atropisomeric KRASG12C inhibitor to support clinical API manufacture. Improvements to the synthesis of a chiral piperazine fragment gave reduced step count and streamlined protecting group strategy via the formation and methanol ring opening of an N-carboxy-anhydride (NCA). The complex atropisomeric nitroquinoline was accessed via an early stage salt-resolution followed by a formal two-part nitromethane-carbonylation, avoiding a high temperature Gould-Jacobs cyclization that previously led to atropisomer racemization. The substrate scope of the formal nitromethane-carbonylation strategy was further explored for a range of ortho-substituted bromo/iodo unprotected anilines.
Assuntos
Proteínas Proto-Oncogênicas p21(ras) , Metano/análogos & derivados , NitroparafinasRESUMO
Radical hydroxymethylation using formaldehyde as a C1 synthon is challenging due to the reversible and endothermic nature of the addition process. Here we report a strategy that couples alkyl iodide building blocks with formaldehyde through the use of photocatalysis and a phosphine additive. Halogen-atom transfer (XAT) from α-aminoalkyl radicals is leveraged to convert the iodide into the corresponding open-shell species, while its following addition to formaldehyde is rendered irreversible by trapping the transient O-radical with PPh3. This event delivers a phosphoranyl radical that re-generates the alkyl radical and provides the hydroxymethylated product.
RESUMO
[This corrects the article DOI: 10.1039/C9SC02616A.].
RESUMO
A divergent strategy for the remote arylation, vinylation and alkylation of nitriles is described. These processes proceed through the photoredox generation of a cyclic iminyl radical and its following ring-opening reaction. The distal nitrile radical is then engaged in nickel-based catalytic cycles to form C-C bonds with aryl bromides, alkynes and alkyl bromides.
RESUMO
OBJECTIVES: Angiopoietins modulate endothelial permeability via endothelial cell junctions. Angiopoietin-2 blocks the angiopoietin-1/Tie-2 interaction that stabilizes these junctions, and elevated plasma angiopoietin-2 levels are associated with vascular leakage. We hypothesized that plasma angiopoietin-1 and angiopoietin-2 levels are associated with indirect markers of increased vascular permeability, organ dysfunction, mortality, and plasma proinflammatory cytokine levels in human septic shock. DESIGN: Multicenter observational cohort study derived from a randomized controlled trial (Vasopressin and Septic Shock Trial of vasopressin versus norepinephrine in septic shock). SETTING: ICUs of hospitals in Canada, Australia, and the United States. PATIENTS: Three hundred forty-one patients in the randomized, controlled Vasopressin and Septic Shock Trial trial of vasopressin versus norepinephrine in septic shock. INTERVENTIONS: None. MEASUREMENT AND MAIN RESULTS: We measured plasma levels of angiopoietin-1 and angiopoietin-2 at study baseline and determined their association with percent fluid overload and acute organ dysfunction and generated a receiver operating characteristic curve for plasma angiopoietin-2 levels versus acute kidney injury. We also determined the association of angiopoietin-1 and angiopoietin-2 levels with hemodynamics, mortality, and plasma cytokine levels. Plasma angiopoietin-2 levels were directly associated with percent fluid overload at baseline (rs = 0.18; p = 0.0008) and at 6 hours (rs = 0.13; p = 0.023), but not at 24 hours (rs = 0.041; p = 0.46). Plasma angiopoietin-2 levels were associated with the development of hepatic (p < 0.0001) and coagulation (p < 0.0001) dysfunction and acute kidney injury (p < 0.0001). Receiver operating characteristic curve had an area under the curve of 0.73 for acute kidney injury. angiopoietin-2 levels were also inversely associated with days alive (r = -0.24; p = 0.010) and positively associated with increased 7-day (log-rank trend chi-square = 5.9; p = 0.015) and 28-day (log-rank chi square = 4.9; p = 0.027) mortality. A threshold of angiopoietin-2 levels above the first quartile (> 5,807 pg/mL) was observed to be associated with increased mortality risk, which aligns with prior studies. Plasma angiopoietin-2 levels were positively associated with plasma cytokine levels, including tumor necrosis factor-α and interleukin-6 at baseline (rs = 0.39; p < 0.0001 and rs = 0.51; p < 0.0001) and at 24 hours (rs = 0.29; p < 0.0001 and rs = 0.41; p < 0.0001). CONCLUSIONS: Increased plasma angiopoietin-2 levels are associated with increased fluid overload, hepatic and coagulation dysfunction, acute kidney injury, mortality, and plasma cytokines in human septic shock. angiopoietin-2 activation may increase vascular leakage leading to increased fluid requirements, organ dysfunction, and death from septic shock.