Ruthenium-catalyzed C-H bond arylations of arenes bearing removable directing groups via six-membered ruthenacycles

Ruthenium-catalyzed direct arylations of phenols bearing removable directing groups were accomplished through carboxylate assistance via six-membered ruthenacycles as key intermediates.

General Ambient Temperature Benzylic Metalations Using Mixed-Metal Li/K-TMP Amide

Highly regioselective benzylic metalations in hydrocarbon solvent have been achieved at rt and 0 °C using a mixed-metal Li/K-TMP amide comprised of KOtBu, BuLi, and 2,2,6,6,-tetramethylpiperidine (TMP(H)). Mixing of KOtBu, BuLi, and TMP(H) in heptane gave a solution of the base mixture which when used in deuterium labeling experiments confirmed the requirement of the three reagent components for both reactivity and selectivity. The reaction protocol is operationally straightforward and found to be applicable to a broad range of substrates. Upon generation of the metalated products, they are reacted in heptane at ambient temperature in a variety of synthetically useful ways. Illustrated examples include generation of the benzyltrimethylsilanes and α,α-bis(trimethylsilyl)toluenes reagents, which are bench-stable surrogates of benzyl anions and α-silyl carbanions utilized for nucleophilic addition and Peterson olefination reactions. Direct C-C couplings mediated by 1,2-dibromoethane provided entries into bibenzyls and [2.2]metacyclophanes. Comparison of reaction outcomes with the same reactions carried out in THF at -78 °C showed no negative effects for conducting the reactions under these milder more user-friendly conditions.

Evaluation of structurally diverse benzoazepines clubbed with coumarins as Mycobacterium tuberculosis agents

Tuberculosis caused by Mycobacterium tuberculosis remains a leading cause of mortality worldwide into 21st century. In continuation with our anti-tuberculosis research programme, in this work, we have prepared molecularly diverse coumarins clubbed with benzothiazepines as well as its aza-analogues-benzodiazepines by molecular hybridization. The resulting compounds were screened for their M. tuberculosis activity against H(37) Rv strains using microplate alamar blue assay. Among the designed diversity, the compounds 5k, 5n and 5o were found significantly active in primary anti-tuberculosis assay at minimum inhibitory concentration <6.25 μm. Moreover, the IC(50) values of 5k and 5o in level-2 screening were observed as >10 μg/mL and 3.63 μg/mL, respectively. Design and synthesis of more focused library and its three-dimensional quantitative structure activity relationship analysis are underway.

Synthesis of 1-(2,6-dichlorophenyl)-3-methylene-1,3-dihydro-indol-2-one derivatives and in vitro anticancer evaluation against SW620 colon cancer cell line

A small library of 2-indolinone derivatives with the 2,6-dichlorophenyl ring at the N(1) position and with varying substitutions including aryl groups at the 3-position were synthesized, and their structures were confirmed by spectral analysis. All molecules were screened for their in vitro cytotoxic activity on SW620 colon cancer cell lines. Among the designed series compounds 4c, 4f and 4j were found to be active at concentrations of 2-15 microg/ml. Some 3D-QSAR models were also built to understand the structure-activity relationship.

Subtle Mitsunobu couplings under super-heating: the role of high-throughput continuous flow and microwave strategies

Fragile Mitsunobu reaction can efficiently be performed under super-heating.

Bu4N+-Controlled Addition and Olefination with Ethyl 2-(Trimethylsilyl)acetate via Silicon Activation

Catalytic Bu4NOAc as silicon activator of ethyl 2-(trimethylsilyl)acetate, in THF, was utilized for the synthesis of β-hydroxy esters, whereas employing catalytic Bu4NOTMS gave α,β-unsaturated esters. The established reaction conditions were applicable to a diverse range of aromatic, heteroaromatic, aliphatic aldehydes and ketones. Reactions were achieved at room temperature without taking any of the specialized precautions that are in place for other organometallics. A stepwise olefination pathway via silylated β-hydroxy esters with subsequent elimination to form the α,β-unsaturated ester has been demonstrated. The key to selective product formation lies in use of the weaker acetate activator which suppresses subsequent elimination whereas stronger TMSO– activator (and base) facilitates both addition and elimination steps. The use of tetrabutyl ammonium salts for both acetate and trimethylsilyloxide activators provide enhanced silicon activation when compared to their inorganic cation counterparts.

Reported patterns of utilization of intravesical therapy in non-muscle-invasive bladder cancer: Results from the BCAN/SUO/AUA/LUGPA electronic survey

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Background: Guidelines recommend intravesical chemotherapy and immunotherapy in the management of non-muscle-invasive bladder cancer (NMIBC) to reduce the risks of recurrence and potentially progression. Nevertheless, recent claims-based analyses have suggested exceedingly low rates of utilization of some of these therapies in practice. In general, there is a paucity of data to inform our understanding of current patterns of care.

Methods: An electronic survey was developed by the Bladder Cancer Advocacy Network (BCAN) to elicit self-reported practices of utilization of intravesical chemo- and immuno-therapy for patients with NMIBC. The survey was circulated to urologists via the AUA, SUO and LUGPA distribution lists. 512 respondents completed the survey.

Results: Overall, 63% of respondents reported routine administration of perioperative mitomycin-c (MMC) after TURBT [80% of SUO respondents vs. 55% of AUA/LUGPA respondents (p<0.001)]. Whereas 5% of respondents reported routine induction therapy with all new low-grade (LG) diagnoses, 99% reported routinely doing so in new high-grade (HG) cases; most commonly with single- agent BCG (94%; vs. 9% BCG/IFN and 5% MMC). Reported induction therapy was higher in the setting of high-volume (77%) or frequently recurrent LG (44%) disease. 89% reported routinely using maintenance therapy for HG, vs. 29% for LG. Reduced strength BCG was most commonly endorsed only in the settings of poor tolerance of full strength (84%) or maintenance (11%), with only 3% endorsing routine use. Routine post-BCG biopsy, even with normal cystoscopy, was endorsed by 28% of respondents, and 64% of respondents used urine-based markers to assess response to intravesical therapy.

Conclusions: Urologists report grade-specific patterns of utilization of intravesical therapy for NMIBC, at rates higher than suggested in some claims-based analyses. Variation exists in post-treatment followup practices. Further study is needed to rectify these self-reported patterns of care with results from claims-based analyses.

No significant financial relationships to disclose.

Risk-specific intensity of surveillance practices in non-muscle-invasive bladder cancer: Results from the BCAN/SUO/AUA/LUGPA electronic survey

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Background: The ideal surveillance regimen for patients with non-muscle-invasive bladder cancer (NMIBC) is uncertain. Given different grade- and stage-specific risks of recurrence and progression, there is some question whether it might be acceptable to pursue less intensive surveillance practices for patients with lower risk disease, and there is a paucity of data on current patterns of care in this area of practice.

Methods: An electronic survey was developed by the Bladder Cancer Advocacy Network (BCAN) to elicit self-reported practices of cystoscopy, cytology, and radiographic testing in the setting of surveillance for patients with a history of NMIBC. The survey was circulated to urologists via the AUA, SUO and LUGPA distribution lists. 512 respondents completed the survey.

Results: Among respondents, 66% report performing cystoscopy every 3 months on all patients for at least the first two years following diagnosis of NMIBC. The remaining 33% report performing surveillance cystoscopy less frequently, 95% of whom report doing so in the setting of low grade pathology. Similarly, 51% report using cytology with every cystoscopy, 23% do so for all high grade cases, and 30% report not using cytology with every cystoscopy. In the absence of recurrence for patients with an initial high grade diagnosis, upper tract reimaging is performed annually in 48%, biannually in 37% and never in 3%. The corresponding figures for patients with an index diagnosis of low grade disease are 14%, 37% and 28%, respectively. In the event of a recurrence in the bladder, 80% of respondents report reimaging the upper tracts for patients with high grade disease, versus 45% in the event of a low grade recurrence.

Conclusions: A substantial number of urologists responding to a survey report using relatively less intensive surveillance practices in patients with lower risk NMIBC. These results suggest a lack of consensus on the ideal intensity of evaluation in this setting, and provide a basis for prospective studies to validate the safest and most cost-effective strategies for surveillance.

No significant financial relationships to disclose.

Patterns of utilization of urine-based markers in non-muscle-invasive bladder cancer: Results from the BCAN/SUO/AUA/LUGPA electronic survey

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Background: In addition to cytologic evaluation, there are currently four urine-based tests approved by the FDA for bladder cancer detection. At this point, the Guidelines panels from the AUA and EAU do not make specific recommendations about the ideal role of these tests. Furthermore, there is a paucity of data on current patterns of care in this area of practice.

Methods: An electronic survey was developed by the Bladder Cancer Advocacy Network (BCAN) to elicit self-reported practices of the use of cytology and urine-based markers in the settings of general use, surveillance, and assessment of response after intravesical therapy for patients with NMIBC. The survey was circulated to urologists via the AUA, SUO and LUGPA distribution lists. 512 respondents completed the survey.

Results: Among all respondents, 93% report sending cytology routinely (25% via barbotage) in general use. In contrast, 37% report using NMP22 in this setting, 54% report using FISH, and 32% (45% of SUO respondents vs. 31% of AUA respondents, p=0.04) responded that there is “no role for urine-based markers in this setting.” Similar proportions were reported in the specific settings of routine surveillance and post-BCG assessment. When presented with the vignette of a positive marker test and negative cytology and cystoscopy, 36% chose to proceed to the OR for biopsy, 37% chose to repeat cystoscopy and cytology in 3 months, 21% chose “no role for markers in this setting” and 13% chose “other.”

Conclusions: In the absence of more specific guidance, the results of this survey suggest considerable variation in the use and interpretation of urine-based markers in NMIBC. FISH is the marker reported to be used most commonly in multiple settings, however 31-45% of respondents report “no role” for any of the tests in their practice. Greater than one out of three respondents reported taking patients for biopsy under anesthesia in the setting of an isolated positive marker. These preliminary data underscore the need for prospective studies to validate the optimal role of urine-based markers in the setting of NMIBC.

No significant financial relationships to disclose.