One-Pot Synthesis of Indolizines via Sequential Rhodium-Catalyzed [2 + 1]-Cyclopropanation, Palladium-Catalyzed Ring Expansion, and Oxidation Reactions from Pyridotriazoles and 1,3-Dienes.

An efficient, one-pot synthetic method for producing functionalized indolizine derivatives was developed via a Rh-catalyzed [2 + 1]-cyclopropanation, Pd-catalyzed ring expansion, and subsequent oxidation using manganese dioxide from pyridotriazoles and 1,3-dienes.

Synthesis of Azepinoindoles via Rhodium-Catalyzed Formal Aza-[4 + 3] Cycloaddition Reaction of 3-Diazoindolin-2-imines with 1,3-Dienes in One-Pot.

Rhodium-catalyzed formal aza-[4 + 3] cycloaddition reaction of 3-diazoindolin-2-imines with 1,3-dienes was demonstrated for the synthesis of azepinoindoles in good to excellent yields in one-pot. First, rhodium-catalyzed [2 + 1] cycloaddition reaction smoothly took place to produce iminyl vinyl cyclopropane intermediate at room temperature in chlorobenzene for 1 h, which was thermally converted to azepinoindoles via aza-Cope rearrangement.

Regional variations in frequency of glycosylated hemoglobin (HbA1c) monitoring in Korea: A multilevel analysis of nationwide data.

PURPOSE: Suboptimal frequency of glycosylated hemoglobin (HbA1c) monitoring is associated with poor diabetes control. We aimed to analyze compliance to HbA1c testing guidelines and explore associated individual and area-level determinants, focusing on regional variation. METHODS: This cross-sectional study between the period of 2012-2013 was conducted by using the Korean National Health Insurance Research Database, and included 45,634 patients diagnosed with diabetes mellitus, who were prescribed any anti-diabetic medications, including insulin. We calculated the proportion of each HbA1c testing frequency (≥1, ≥2, or ≥4 times per year) stratified by 17 administrative regions. Multilevel and multivariate logistic analyses were performed with regional (proportion of farmer population) and individual characteristics (age, sex, income level, duration of diabetes, and most visited medical institution). RESULTS: Overall, 67.3% of the patients received≥1 HbA1c test per year; 37.8% and 6.1% received ≥2 and ≥4 tests per year, respectively. Those managed in secondary-level hospitals or clinics and those living in rural areas were less likely to receive HbA1c testing. Even after adjusting for individual and regional level characteristics, significant area level variation was observed (variance participant coefficients were 7.91%, 9.58%, and 14.43% for testing frequencies of ≥1, ≥2, and ≥4 times a year, respectively). CONCLUSIONS: The frequency of HbA1c monitoring is suboptimal in Korea, especially in rural areas. Moreover, significant regional variation was observed, implying a contextual effect. This suggests the need for developing policy actions to improve HbA1c monitoring. In particular, access to HbA1c testing in rural primary care clinics must be improved.

Synthesis of Benzofulvenes through Rhodium-Catalyzed Transannulation of Enynyl Triazoles.

Rhodium-catalyzed denitrogenative cyclization of (E)-ethyl 2-(1-alkyl and arylsulfonyl-1H-1,2,3-triazol-4-yl)-3-aryl acrylate generated from (E)-ethyl 2-benzylidenebut-3-ynoates and N-sulfonyl azides in the presence of a copper catalyst was developed for the synthesis of a large number of functionalized benzofulvenes. Moreover, the synthesis of benzofulvenes was demonstrated as a one-pot method through tandem copper-catalyzed [3 + 2] cycloaddition and rhodium-catalyzed denitrogenative cyclization from (E)-ethyl 2-benzylidenebut-3-ynoates and N-sulfonyl azides.

In situ generation of phosphoryl alkylindiums and their synthetic application to arylalkyl phosphonates via palladium-catalyzed cross-coupling reactions.

Phosphoryl alkylindium reagents are generated in situ from the direct insertion of indium with bromoalkyl phosphonates in the presence of CuCl, and their synthetic application to arylalkyl phosphonates is reported via a Pd-catalyzed cross-coupling reaction with tolerance of a diversity of functional groups including ester, ketone, aldehyde, nitrile, nitro, trifluoromethyl, chloride, methoxy, hydroxy, and amino.

Mild copper-TBAF-catalyzed N-arylation of sulfoximines with aryl siloxanes.

An efficient copper-TBAF-catalyzed C-N bond formation of sulfoximines with arylsiloxanes in dichloromethane at room temperature, affording the desired N-aryl sulfoximines in good to excellent yields under an oxygen atmosphere, is reported. This method complements the existing synthetic approaches due to some advantageous properties of arylsiloxanes such as availability, low toxicity, ease of handling, high stability, and environmental benignity under mild reaction conditions, thus opening a new approach to practical C-N bond formation.

Diastereoselective N-sulfonylaminoalkenylation of azulenes from terminal alkynes and azides via N-sulfonyl-1,2,3-triazoles.

The development of rhodium-catalyzed diastereoselective N-sulfonylaminoalkenylation of azulenes using N-sulfonyltriazoles is described. This procedure can be successfully applied to rhodium-catalyzed diastereoselective N-sulfonylaminoalkenylation of azulenes starting from terminal alkynes and N-sulfonylazides via a three-component semi-one-pot process.

Rhodium-catalyzed oxidative cyclization of arylphosphonic acid monoethyl esters with alkenes: efficient synthesis of benzoxaphosphole 1-oxides.

Rhodium-catalyzed tandem oxidative alkenylation and an intramolecular oxy-Michael reaction were developed using arylphosphonic acid monoethyl esters and alkenes under aerobic conditions, which produced benzoxaphosphole 1-oxides in good to excellent yields.

Copper-catalyzed intramolecular hydroalkoxylation of α-(1-hydroxy-1-alkyl- and -aryl)methylallenoates by a 5-endo mode for preparation of 2-alkyl- and 2-aryl-2,5-dihydrofurans.

Ethyl α-(1-hydroxy-1-alkyl)methylallenoates and α-(1-hydroxy-1-aryl)methylallenoates containing not only electron-donating groups but also an electron-withdrawing group on the aryl group at the α-position have been shown to undergo an efficient and selective copper-catalyzed intramolecular hydroalkoxylation to give functionalized 3-ethoxycarbonyl-2-alkyl- and -aryl-2,5-dihydrofurans in good to excellent yields through a 5-endo mode.

Long-distance simultaneous measurement of strain and temperature based on a fiber Raman laser with a single fiber Bragg grating embedded on a quartz plate.

We propose and experimentally demonstrate long-distance remote simultaneous measurement of strain and temperature based on a Raman fiber laser with a single fiber Bragg grating embedded on a quartz plate. A Raman fiber laser output with a high extinction ratio of more than approximately 50 dB is achieved by the fiber grating cavity. In the sensing probe, half of the fiber Bragg grating is fixed steadily on the quartz plate to respond to temperature only, while the other half of the grating is free to respond to both temperature and strain. Based on the proposed scheme, lasing wavelength shift and separation occur with temperature and strain change, respectively. Efficient simultaneous measurement of strain and temperature for long-distance sensing applications of more than 50 km is readily obtained.

Multiwavelength Raman-fiber-laser-based long-distance remote sensor for simultaneous measurement of strain and temperature.

We propose a simple and flexible multiwavelength Raman-fiber-laser-based long-distance remote-sensing scheme for simultaneous measurement of strain and temperature by use of fiber Bragg gratings. By combining two uniform fiber Bragg gratings with a tunable chirped fiber grating, we readily achieve simultaneous two-channel sensing probes with a high extinction ratio of more than approximately 50 dB over a 50-km distance. When strain and temperature are applied, lasing wavelength separation and shift occur, respectively, since the two uniform fiber Bragg gratings have identical material composition and different cladding diameters. This allows simultaneous measurement of strain and temperature for long-distance sensing applications of more than 50 km.

Development of a multiwavelength Raman fiber laser based on phase-shifted fiber Bragg gratings for long-distance remote-sensing applications.

We propose a simple and flexible multiwavelength Raman fiber laser based on phase-shifted fiber Bragg gratings (FBGs) and a tunable chirped FBG. Using a simple multiwavelength Raman laser configuration with a single phase-shifted FBG and a tunable chirped FBG, we readily achieved simultaneous two-channel sensing probes with a high extinction ratio of more than 50 dB over a 50-km distance. The multiwavelength output was stable and the peak fluctuation was less than 0.5 dB. The temperature and strain sensitivities are estimated to be 10.1 pm/degrees C and 7.5 pm/microstrain, respectively.

Investigation of Raman fiber laser temperature probe based on fiber Bragg gratings for long-distance remote sensing applications.

We demonstrate a practical and simple, all fiber Bragg grating (FBG) based Raman laser sensing probe for long-distance, remote temperature sensing application. Using multiple laser cavities based on FBG's and a tunable chirped FBG, we obtain the simultaneous multi-channel remote temperature sensing operation at a 50 km distance. The temperature sensitivity is measured to be 7.15 pm/ degrees C.