Synthesis of the Indole-Based Inhibitors of Bacterial Cystathionine γ-Lyase NL1-NL3.

Bacterial cystathionine γ-lyase (bCSE) is the main producer of H2S in pathogenic bacteria such as Staphylococcus aureus, Pseudomonas aeruginosa, etc. The suppression of bCSE activity considerably enhances the sensitivity of bacteria to antibiotics. Convenient methods for the efficient synthesis of gram quantities of two selective indole-based bCSE inhibitors, namely (2-(6-bromo-1H-indol-1-yl)acetyl)glycine (NL1), 5-((6-bromo-1H-indol-1-yl)methyl)- 2-methylfuran-3-carboxylic acid (NL2), as well as a synthetic method for preparation 3-((6-(7-chlorobenzo[b]thiophen-2-yl)-1H-indol-1-yl)methyl)- 1H-pyrazole-5-carboxylic acid (NL3), have been developed. The syntheses are based on the use of 6-bromoindole as the main building block for all three inhibitors (NL1, NL2, and NL3), and the designed residues are assembled at the nitrogen atom of the 6-bromoindole core or by the substitution of the bromine atom in the case of NL3 using Pd-catalyzed cross-coupling. The developed and refined synthetic methods would be significant for the further biological screening of NL-series bCSE inhibitors and their derivatives.

(2-Fluoroallyl)pyridinium tetrafluoroborates: novel fluorinated electrophiles for Pd-catalyzed allylic substitution.

An efficient two-step approach to 2-fluoroallyl amines was developed that involves the synthesis of (2-fluoroallyl)pyridinium tetrafluoroborates from readily available gem-bromofluorocyclopropanes and the application of the former as novel and stable 2-fluoroallyl electrophiles for Pd-catalyzed allylic substitution.

(2-Fluoroallyl)boration of Ketones with (2-Fluoroallyl)boronates.

Efficient routes toward activation of gem-chlorofluorocyclopropane-derived (2-fluoroallyl)boronates for allylboration of various ketones including functionalized and low-reactive ones were developed. Increasing the boron electrophilicity by the transformation of a boronate moiety into a borinic ester with nBuLi/trifluoroacetic anhydride (TFAA) makes (2-fluoroallyl)boration of acetyl arenes/hetarenes and aliphatic ketones possible with high diastereoselectivity. For low-reactive or sterically hindered ketones (e.g., benzophenone, adamantanone), "CuF"-based catalysts were developed: (NHC)CuF·HF and (NHC)CuOTf in the presence of an excess of KHF2 (NHC = IPr, SIPr, IPrCl).

A Systematic Review and International Web-Based Survey of Randomized Controlled Trials in the Perioperative and Critical Care Setting: Interventions Increasing Mortality.

OBJECTIVE: Reducing mortality is a key target in critical care and perioperative medicine. The authors aimed to identify all nonsurgical interventions (drugs, techniques, strategies) shown by randomized trials to increase mortality in these clinical settings. DESIGN: A systematic review of the literature followed by a consensus-based voting process. SETTING: A web-based international consensus conference. PARTICIPANTS: Two hundred fifty-one physicians from 46 countries. INTERVENTIONS: The authors performed a systematic literature search and identified all randomized controlled trials (RCTs) showing a significant increase in unadjusted landmark mortality among surgical or critically ill patients. The authors reviewed such studies during a meeting by a core group of experts. Studies selected after such review advanced to web-based voting by clinicians in relation to agreement, clinical practice, and willingness to include each intervention in international guidelines. MEASUREMENTS AND MAIN RESULTS: The authors selected 12 RCTs dealing with 12 interventions increasing mortality: diaspirin-crosslinked hemoglobin (92% of agreement among web voters), overfeeding, nitric oxide synthase inhibitor in septic shock, human growth hormone, thyroxin in acute kidney injury, intravenous salbutamol in acute respiratory distress syndrome, plasma-derived protein C concentrate, aprotinin in high-risk cardiac surgery, cysteine prodrug, hypothermia in meningitis, methylprednisolone in traumatic brain injury, and albumin in traumatic brain injury (72% of agreement). Overall, a high consistency (ranging from 80% to 90%) between agreement and clinical practice was observed. CONCLUSION: The authors identified 12 clinical interventions showing increased mortality supported by randomized controlled trials with nonconflicting evidence, and wide agreement upon clinicians on a global scale.

A Systematic Review and International Web-Based Survey of Randomized Controlled Trials in the Perioperative and Critical Care Setting: Interventions Reducing Mortality.

The authors aimed to identify interventions documented by randomized controlled trials (RCTs) that reduce mortality in adult critically ill and perioperative patients, followed by a survey of clinicians' opinions and routine practices to understand the clinicians' response to such evidence. The authors performed a comprehensive literature review to identify all topics reported to reduce mortality in perioperative and critical care settings according to at least 2 RCTs or to a multicenter RCT or to a single-center RCT plus guidelines. The authors generated position statements that were voted on online by physicians worldwide for agreement, use, and willingness to include in international guidelines. From 262 RCT manuscripts reporting mortality differences in the perioperative and critically ill settings, the authors selected 27 drugs, techniques, and strategies (66 RCTs, most frequently published by the New England Journal of Medicine [13 papers], Lancet [7], and Journal of the American Medical Association [5]) with an agreement ≥67% from over 250 physicians (46 countries). Noninvasive ventilation was the intervention supported by the largest number of RCTs (n = 13). The concordance between agreement and use (a positive answer both to "do you agree" and "do you use") showed differences between Western and other countries and between anesthesiologists and intensive care unit physicians. The authors identified 27 clinical interventions with randomized evidence of survival benefit and strong clinician support in support of their potential life-saving properties in perioperative and critically ill patients with noninvasive ventilation having the highest level of support. However, clinician views appear affected by specialty and geographical location.

(2-Fluoroallyl)boronates: new reagents for diastereoselective 2-fluoroallylboration of aldehydes.

A Pd-catalyzed borylation of 2-fluoroallyl chlorides with B2pin2 in the presence of [(2-MeAll)PdCl]2/TMEDA or [(2-MeAll)Pd(IPr)Cl] was developed to afford (2-fluoroallyl)pinacolboronates with high Z-selectivity. The products proved to be useful for anti-selective 2-fluoroallylboration of aromatic and aliphatic aldehydes.

Phosphocreatine in Cardiac Surgery Patients: A Meta-Analysis of Randomized Controlled Trials.

OBJECTIVE: There is experimental evidence that phosphocreatine (PCr) can decrease ischemia/reperfusion injury of the heart. The authors investigated if PCr would improve heart performance as compared with standard treatment in cardiac surgery. DESIGN: Meta-analysis of randomized controlled trials. SETTING: Hospitals. PARTICIPANTS: Adult and pediatric patients undergoing cardiac surgery. INTERVENTIONS: The ability of PCr to improve cardiac outcomes as compared with standard treatment was investigated. MEASUREMENTS AND MAIN RESULTS: PubMed/Medline, Embase, Scopus, Cochrane Library, China National Knowledge Infrastructure, WANGFANG DATA, and VIP Paper Check System were searched to March 1 2017. The authors included 26 randomized controlled trials comprising 1,948 patients. Random and fixed-effects models were used to estimate odds ratio (OR) and mean difference (MD) with 95% confidence interval (CI). PCr use was associated with reduced rates of intraoperative inotropic support (27% v 44%; OR 0.47, 95% CI 0.35-0.61; p < 0.001), major arrhythmias (16% v 28%; OR 0.44, 95% CI 0.27-0.69; p < 0.001), as well as increased spontaneous recovery of the cardiac rhythm immediately after aortic declamping (50% v 34%; OR 2.45, 95% CI 1.82-3.30; p < 0.001) as compared with standard treatment. The use of PCr decreased myocardial damage and augmented left ventricular ejection fraction in the postoperative period; however, MD for these outcomes were small and do not seem to be clinically significant. CONCLUSIONS: In randomized trials, PCr administration was associated with reduced rates of intraoperative inotropic support and major arrhythmias, and increased spontaneous recovery of the cardiac rhythm after aortic declamping. Large multicenter evidence is needed to validate these findings.

Trifluoromethylation of aryl and heteroaryl halides with fluoroform-derived CuCF3: scope, limitations, and mechanistic features.

Fluoroform-derived CuCF3 recently discovered in our group exhibits remarkably high reactivity toward aryl and heteroaryl halides, performing best in the absence of extra ligands. A broad variety of iodoarenes undergo smooth trifluoromethylation with the "ligandless" CuCF3 at 23-50 °C to give the corresponding benzotrifluorides in nearly quantitative yield. A number of much less reactive aromatic bromides also have been trifluoromethylated, including pyridine, pyrimidine, pyrazine, and thiazole derivatives as well as aryl bromides bearing electron-withdrawing groups and/or ortho substituents. Only the most electrophilic chloroarenes can be trifluoromethylated, e.g., 2-chloronicotinic acid. Exceptionally high chemoselectivity of the reactions (no side-formation of arenes, biaryls, and C2F5 derivatives) has allowed for the isolation of a large number of trifluoromethylated products in high yield on a gram scale (up to 20 mmol). The CuCF3 reagent is destabilized by CuX coproduced in the reaction, the magnitude of the effect paralleling the Lewis acidity of CuX: CuCl > CuBr > CuI. While S(N)Ar and S(RN)1 mechanisms are not operational, there is a well-pronounced ortho effect, i.e., the enhanced reactivity of ortho-substituted aryl halides 2-RC6H4X toward CuCF3. Intriguingly, this ortho-effect is observed for R = NO2, COOH, CHO, COOEt, COCH3, OCH3, and even CH3, but not for R = CN. The fluoroform-derived CuCF3 reagent and its reactions with haloarenes provide an unmatched combination of reactivity, selectivity, and low cost.

Boronyl Borinic Esters: Preparation as B2 pin2 /sec BuLi/TFAA Adducts, Structural Insights and Reactivity in Pd-catalyzed Allylic Borylation.

Novel boronyl borinic ester I was generated by quenching the B2 pin2 /sec BuLi-ate complex with trifluoroacetic acid anhydride (TFAA) via ring-opening in the 1,3,2-dioxaborolane moiety on ate-boron. Detailed NMR studies of the B2 pin2 /sec BuLi-ate complex in solution and in solid state allowed us to assume its oligomeric nature in solids with only ate-boron involved in the oligomerization process. The O-trifluoroacetyl pinacolate residue on borinic ester I initially formed on quenching with TFAA undergoes an unusual intramolecular transesterification with the carbonyl group of trifluoroacetyl forming othroester moiety in a few hours at r. t. to give boronyl borinic ester II. A solution of these reagents I/II was proved to be efficient for borylation of (2-fluoroallyl)pyridinium salts that are highly base sensitive.

Direct cupration of fluoroform.

We have found the first reaction of direct cupration of fluoroform, the most attractive CF(3) source for the introduction of the trifluoromethyl group into organic molecules. Treatment of CuX (X = Cl, Br, I) with 2 equiv of MOR (M = K, Na) in DMF or NMP produces novel alkoxycuprates that readily react with CF(3)H at room temperature and atmospheric pressure to give CuCF(3) derivatives. The CuCl and t-BuOK (1:2) combination provides best results, furnishing the CuCF(3) product within seconds in nearly quantitative yield. As demonstrated, neither CF(3)(-) nor CF(2) mediate the Cu-CF(3) bond formation, which accounts for its remarkably high selectivity. The fluoroform-derived CuCF(3) solutions can be efficiently stabilized with TREAT HF to produce CuCF(3) reagents that readily trifluoromethylate organic and inorganic electrophiles in the absence of additional ligands such as phenanthroline. A series of novel Cu(I) complexes have been structurally characterized, including K(DMF)[Cu(OBu-t)(2)] (1), Na(DMF)(2)[Cu(OBu-t)(2)] (2), [K(8)Cu(6)(OBu-t)(12)(DMF)(8)(I)](+) I(-) (3), and [Cu(4)(CF(3))(2)(C(OBu-t)(2))(2)(µ(3)-OBu-t)(2)] (7).

A Versatile Equilibrium Method for the Synthesis of High-Strength, Ladder-like Polyphenylsilsesquioxanes with Finely Tunable Molecular Parameters.

A versatile equilibrium method for synthesizing ladder-like polyphenylsilsesquioxanes (L-PPSQs) with various molecular weights (from 4 to 500 kDa) in liquid ammonia was developed. The effect of diverse parameters, such as temperature, monomer concentration, reaction time, addition or removal of water from the reaction medium, on the polycondensation process was determined. The molecular weight characteristics and structure of the L-PPSQ elements obtained were determined by GPC, 1H, 29Si NMR, IR spectroscopy, viscometry, and PXRD methods. The physicochemical properties of L-PPSQs were determined by TGA and mechanical analyses.

Oxidative stress and liver monooxygenase function after heart valve surgery.

BACKGROUND AND OBJECTIVES: this prospective study was carried out to evaluate oxidative stress and liver monooxygenase function after cardiac surgery in patients with acquired valvular heart disease. METHODS: 97 patients were studied. Oxidative stress was quantified with malondialdehyde, coupled trienes, hepatocuprein, and catalase activity. Liver monooxygenase function was evaluated with antipyrine pharmacokinetics. For statistical analyses, the Dunnett test and Pearson's correlation coefficient were used. RESULTS: on the 1st-2nd postoperative days, high lipid peroxidation activation (malondialdehyde: 9.6 ± 2.7 vs. 6.9 ± 2.0 nmol mL(-1), p <0.05) and a significant decrease in liver monooxygenase function (antipyrine clearance: 18.3 ± 11.1 vs. 39.0 ± 18.9 mL kg(-1)h(-1), p <0.05) were revealed. On the 3rd-4th and 11th-12th postoperative days, the intensity of oxidative stress decreased and monooxygenase function returned to baseline (antipyrine clearance: 45.6 ± 17.9 vs. 39.0 ± 18.9 mL kg(-1)h(-1)). The analysis showed a negative relationship between oxidative stress and liver monooxygenase function. CONCLUSION: patients undergoing surgery for acquired valvular heart disease have considerable oxidative stress and a decrease in liver monooxygenase function on the 1st-2nd postoperative days. Activation of lipid peroxidation is one of the main reasons for suppression of microsomal monooxygenases activity. A slowdown of liver microsomal oxidation might change the pharmacokinetic response of patients under drug therapy.