Orthogonal reactivity modes offer substantial opportunities for rapid construction of complex small molecules. However, most strategies for imparting orthogonality to cross-coupling reactions rely on differential protection of reactive sites, greatly reducing both atom and step economies. Reported here is a strategy for orthogonal cross-coupling wherein a mechanistically distinct activation mode for transmetalation of sp3-hybridized organoboron reagents enables C-C bond formation in the presence of various protected and unprotected sp2-hybridized organoborons. This manifold has the potential for broad application, because orthogonality is inherent to the activation mode itself. The diversification potential of this platform is shown in the rapid elaboration of a trifunctional lynchpin through various transition metal-catalyzed processes without nonproductive deprotection or functional group manipulation steps.
Primitive meteorites contain various
classes of organic compounds.
Because the molecular distribution in these meteorites is not fully
clarified, we do not yet understand the comprehensive formation mechanism(s)
of extraterrestrial organic compounds. In this study, diverse and
abundant alkylated homologues of N-containing cyclic compounds were
identified in the methanol extract of the Murchison meteorite by electrospray
ionization using high-performance liquid chromatography/ultrahigh-resolution
mass spectrometry. More than 600 positive ions were assigned to C
n
H
m
N+ and C
n
H
m
N2
+, in which saturated and unsaturated alkylated
pyridines and alkylimidazoles are predominant. Both can be synthesized
from aldehydes and ammonia through aldol condensation and imine formation
under an alkaline environment. Further redox reactions could have
proceeded to make these molecules evolve to various CHN compounds,
including alkylpiperidines and pyridine carboxylic acids. This study
indicates that aldol condensation and formose reaction with ammonia
are an important mechanism for the molecular evolution of N-containing
compounds in the asteroid.
BackgroundCardiac troponin I (cTnI) is useful for assessing hypertrophic cardiomyopathy (HCM) in cats.ObjectiveTo measure plasma cTnI concentrations in healthy cats and evaluate the clinical utility of cTnI in determining the severity of HCM.AnimalsClinically healthy cats (n = 88) and cats with HCM (n = 93).MethodsMulticenter prospective study. Cats with HCM, including hypertrophic obstructive cardiomyopathy at various stages, were diagnosed using echocardiography. Plasma cTnI concentrations were analyzed by a commercial laboratory. Receiver‐operating characteristic curve analysis was used to evaluate the accuracy of plasma cTnI concentrations to detect HCM.ResultsThe median cTnI concentration was 0.027 ng/mL (interquartile range, 0.012‐0.048 ng/mL) in healthy cats. Concentrations were significantly higher in diseased cats than in healthy controls, and concentrations were significantly higher in cats with heart failure than in asymptomatic cats. A plasma cTnI concentration of 0.163 ng/mL had a sensitivity of 62.0% and specificity of 100% when used to distinguish normal cats from asymptomatic HCM cats without left atrial dilatation. A cutoff of 0.234 ng/mL had high sensitivity (95.0%) and specificity (77.8%) for assessing heart failure. The areas under the receiver‐operating characteristic curves were 0.85 and 0.93, respectively.Conclusions and Clinical ImportanceIncreased cTnI concentrations reflect the severity of HCM. If other causes of cardiac injury are ruled out, plasma cTnI concentration may be useful for predicting the severity of HCM in cats.
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