Applied Organometallics: Cp*Co(III)-Catalysed C-H Functionalisation as a Maturing Tool for the Synthesis of Heterocyclic Compounds

Heterocycle compounds are prevalent throughout the natural world and therefore it is unsurprising that they have become a key component in many pharmaceutically relevant molecules. Unfortunately, synthetic methods for their preparation are often complicated and exhibit poor sustainability. In order to develop more efficient and sustainable routes to the synthesis of these useful and valuable heterocyclic compounds chemists have started to develop new innovative approaches. One approach which has provided a number of successes in recent times are synthetic procedures operating through a key direct C?H bond functionalisation step. This chapter highlights the state-of-the-art for preparing a diverse range of heterocyclic compounds using a cobalt-catalysed C?H bond functionalisation approach, specifically applying Cp*Co(iii)-type catalysts

Synthesis Imaging of Dense Molecular Gas in the N113 HII Region of the Large Magellanic Cloud

We present aperture synthesis imaging of dense molecular gas in the Large Magellanic Cloud, taken with the prototype millimeter receivers of the Australia Telescope Compact Array (ATCA). Our observations of the N113 HII region reveal a condensation with a size of ~6" (1.5 pc) FWHM, detected strongly in the 1-0 lines of HCO+, HCN and HNC, and weakly in C_2H. Comparison of the ATCA observations with single-dish maps from the Mopra Telescope and sensitive spectra from the Swedish-ESO Submillimetre Telescope indicates that the condensation is a massive clump of ~10^4 solar masses within a larger ~10^5 solar mass molecular cloud. The clump is centered adjacent to a compact, obscured HII region which is part of a linear structure of radio continuum sources extending across the molecular cloud. We suggest that the clump represents a possible site for triggered star formation. Examining the integrated line intensities as a function of interferometer baseline length, we find evidence for decreasing HCO+/HCN and HCN/HNC ratios on longer baselines. These trends are consistent with a significant component of the HCO+ emission arising in an extended clump envelope and a lower HCN/HNC abundance ratio in dense cores.Comment: 10 pages, 6 figures, to appear in Ap

The structure of the southern Milky Way

The skies of the Southern hemisphere contain many of the objects important in the studies of galactic structure and stellar evolution. Apart from the Magellanic Clouds, the two nearest galaxies, there is a most interesting area of the Milky Way - that near the direction of the galactic centre. The greater part of it can be observed at observatories situated in the Northern hemisphere, but the region between l11 = 290° and lII = 350° is inaccessible. There is a marked disparity between our knowledge of the Northern and Southern Milky Ways, and this is reflected particularly in our understanding of spiral structure, the optical interpretation of which depends almost entirely on Northern hemisphere observations.The main object of this thesis is to add to the knowledge of the structure of the Southern Milky Way by: (a) A study of the size and distribution of H II regions. (b) The studies of two star concentrations - a visual grouping of early-type stars, and a young cluster. In (a), a photographic survey for the detection of H II regions in the Southern Milky Way is carried out. Their distribution and apparent sizes as a function of galactic longitude are used to construct a qualitative representation of spiral structure which is compared with the current models. The aims of the investigations carried out in (b) are to study the characteristics of visual groupings of early-type stars and to aid the determination of distances of spiral arms in the Southern Milky Way

Assessing Group Efficacy: Comparing Three Methods of Measurement

Two hundred eighty-two undergraduate students (94 groups) participated in a laboratory study designed to compare three methods of assessing group efficacy: an aggregate of self-efficacy perceptions, an aggregate of individual perceptions of group efficacy, and a consensual approach. Findings indicate that the three methods of measuring group efficacy do not differ in their capacity to discriminate high and moderate task-difficulty conditions nor do they differ in terms of their consistency, the magnitude of their relationship with goals, or the degree to which they are affected by performance. Findings suggest that any of the three methods can be applied when studying the effects of group efficacy, at least for tasks with low interdependence

Impact of gender and generational differences in work values and attitudes in an Arab culture

In this article, the work values and attitudes of 241 nationals from the United Arab Emirates are examined. Specifically, we assessed the impact of generational membership and gender on the Islamic work ethic, individualism, attitudes toward women at work, and perceptions of the utility of wasta. Results suggest that values and attitudes held by people in the Middle East are changing on the one hand (e.g., individualism) but are also deeply held on the other (e.g., the Islamic work ethic). Results also suggest that the perceptions about the utility of wasta differ across generations. The implications of these findings and suggestions for future research are discussed. © 2006 Wiley Periodicals, Inc

Chemoselective cycloadditions to epoxide derivatives of erucic acid with CO2 and CS2: controlled access to value-added bio-derived compounds

The potential for application of bio-derived molecules in our everyday lives is attracting vast interest as attention moves towards development of a truly circular and sustainable economy. Whilst a large number of molecules are naturally available and contain a variety of functional groups, few of these compounds are able to be immediately transferred to applications where they can directly replace established oil-derived species. This issue presents both a challenge and an opportunity for the synthetic chemistry community. This study demonstrates how erucic acid, a molecule containing an olefin and a carboxylic acid, which is readily available from commonly cultivated rapeseed oils, can be used as a platform to be chemoselectively converted into a range of value-added compounds using established and high yielding synthetic procedures. In particular, the work showcases approaches towards the chemoselective (and in cases regioselective) oxidation with m-CPBA and incorporation of cyclic carbonate and cyclic dithiocarbonate functionalities which have potential to be employed in a range of applications. Expedient routes to unusual derivatives containing both cyclic carbonate and cyclic dithiocarbonates are also presented taking advantage of the distinct reactivities of the two different epoxides in the intermediate compounds. This work also provides a rare example of the synthesis of internal cyclic dithiocarbonates. These new products have potential to be applied as monomers in the growing field of bio-based non-isocyanate polyurethane synthesis.Comunidad de MadridMinisterio de Ciencia, Innovación y UniversidadesUniversidad de Alcal

Tale of three (media) cities

In the early years of the twenty-first century, three of the 23 Arab nations &ndash; Jordan, the United Arab Emirates and Egypt &ndash; have established media cities in the hope that media and knowledge-based industries will push their economies forward. All three cities are the direct result of government policy and planning. The intention is that a combination of media, business, technology and finance will become inexorably linked and that the resulting synergy will produce thousands of jobs. The cities offer financial benefits to companies located in the special zones created for the cities. As well as generating jobs and leapfrogging their economies into the 21st century, these cities are also meant to be shining symbols of modernity in societies that have tended to look backwards rather than forwards. This paper considers the vision behind these cities, who owns them, the business models employed and their likelihood of success. It also considers the key issue of freedom of expression and the free flow of information in these cities, in the context of societies that traditionally have restricted the flow of information and adopted a different interpretation of freedom of expression, compared with the West&rsquo;s approach.<br /

Rotation periods of late-type stars in the young open cluster IC 2602

We present the results of a monitoring campaign aimed at deriving rotation periods for a representative sample of stars in the young (30 Myr) open cluster IC 2602. Rotation periods were derived for 29 of 33 stars monitored. The periods derived range from 0.2d (one of the shortest known rotation periods of any single open cluster star) to about 10d (which is almost twice as long as the longest period previously known for a cluster of this age). We are able to confirm 8 previously known periods and derive 21 new ones, delineating the long period end of the distribution. Despite our sensitivity to longer periods, we do not detect any variables with periods longer than about 10d. The combination of these data with those for IC 2391, an almost identical cluster, leads to the following conclusions: 1) The fast rotators in a 30 Myr cluster are distributed across the entire 0.5 < B-V < 1.6 color range. 2) 6 stars in our sample are slow rotators, with periods longer than 6d. 3) The amplitude of variability depends on both the color and the period. The dependence on the latter might be important in understanding the selection effects in the currently available rotation period database and in planning future observations. 4) The interpretation of these data in terms of theoretical models of rotating stars suggests both that disk-interaction is the norm rather than the exception in young stars and that disk-locking times range from zero to a few Myr.Comment: 23 pages, 8 figures, accepted for publication in the Astrophysical Journa

Chandra Observations of the Crab-like Supernova Remnant G21.5-0.9

Chandra observations of the Crab-like supernova remnant G21.5-0.9 reveal a compact central core and spectral variations indicative of synchrotron burn-off of higher energy electrons in the inner nebula. The central core is slightly extended, perhaps indicating the presence of an inner wind-shock nebula surrounding the pulsar. No pulsations are observed from the central region, yielding an upper limit of ~40% for the pulsed fraction. A faint outer shell may be the first evidence of the expanding ejecta and blast wave formed in the initial explosion, indicating a composite nature for G21.5-0.9.Comment: 4 pages, 2 figures, formatted with emulateapj, submitted to ApJ