RESUMO
The efficient synthesis of fluoroalkylated pyrazolo[1,5-c]quinazolines by reactions of 3-diazoindolin-2-ones with methyl ß-fluoroalkylpropionates has been achieved. This protocol affords two regioisomers of fluoroalkylated pyrazolo[1,5-c]quinazolines with excellent yields in total. The dipolarophilicity of methyl ß-fluoroalkylpropionates enhanced by perfluoroalkyl groups is crucial for the high efficiency of this [3 + 2] cycloaddition reaction.
RESUMO
The classical Pummerer rearrangement of 2,2,2-trifluoroethylaryl sulfoxide with trifluoracetic anhydride (TFAA) affords the S,O-acetal efficiently. In the presence of trifluoracetic acid (TFA) as the co-solvent, the S,O-acetal can regenerate reactive thionium intermediate of Pummerer rearrangement. When employing arenes as nucleophiles, this strategy produces corresponding 1-thiyl-2,2,2-trifluoroethyl arenes with excellent yields under metal-free conditions.
Assuntos
Acetais , Sulfóxidos , AlquilaçãoRESUMO
BACKGROUND: We performed this meta-analysis to evaluate the efficacy of intrathecal sufentanil in preventing shivering during neuraxial anesthesia. MATERIAL/METHODS: We searched the Cochrane Library, PubMed, and Embase for all randomized controlled trials (RCT) on use of intrathecal sufentanil for preventing shivering during neuraxial anesthesia. References of retrieved articles were also screened. The quality of the studies was evaluated by the method recommended by the Cochrane Collaboration. Meta-analysis was conducted using the Cochrane Collaboration's RevMan 5.3 software. The primary outcome was incidence and severity of shivering, and the secondary outcomes were drug-related complications of pruritus, nausea, vomiting, hypotension, and bradycardia. RESULTS: Eight original RCTs investigating a total of 1032 patients, of whom 599 received sufentanil and 473 received placebo, met the inclusion criteria. Compared to the placebo group, sufentanil did not reduce incidence of shivering (OR, 0.60; 95% CI, 0.35 to 1.01; P=0.06), but it increased the incidence of pruritus (OR, 12.52; 95% CI, 5.07 to 30.91; P<0.00001). Compared to the placebo group, sufentanil did not increase the incidence of nausea (OR, 0.69; 95% CI, 0.41 to 1.16; P=0.16), hypotension (OR, 0.93; 95% CI, 0.62 to 1.41; P=0.74), or bradycardia (OR, 0.86; 95% CI, 0.41 to 1.82; P=0.70). In addition, sufentanil reduced the incidence of vomiting during neuraxial anesthesia (OR, 0.45; 95% CI, 0.22 to 0.92; P=0.03). CONCLUSIONS: Neither epidural nor subarachnoid intrathecal sufentanil reduced shivering during neuraxial anesthesia, but it did increase the incidence of pruritus.
