The importance of reflection in higher education and across disciplinary fields is widely recognised and it is generally included in university graduate attributes, professional standards and programme objectives. Furthermore, reflection is commonly embedded into assessment requirements in higher education subjects, often without necessary scaffolding or clear expectations for students. Despite the rhetoric around the importance of reflection for ongoing learning, there is scant literature on any systematic, developmental approach to teaching reflective learning across higher education programmes/courses. Given that professional or academic reflection is not intuitive, and requires specific pedagogic intervention to do well, a programme/course-wide approach is essential. This paper draws on current literature to theorise a new, transferable and customisable model for teaching and assessing reflective learning across higher education, which foregrounds and explains the pedagogic field of higher education as a multidimensional space. We argue that explicit and strategic pedagogic intervention, supported by dynamic resources, is necessary for successful, broad-scale approaches to reflection in higher education.
A Cu-catalyzed method has been identified for aerobic oxidative dimerization of carbazoles and diarylamines to the corresponding N-N coupled bicarbazoles and tetraarylhydrazines. The reactions proceed under mild conditions (1 atm O, 60-80 °C) with a catalyst composed of CuBr·dimethylsulfide and N, N-dimethylaminopyridine. Reactions between carbazole and diarylamines show unusually selective cross-coupling, even with a 1:1 ratio of the two substrates. This behavior was found to arise from reversible formation of the tetraarylhydrazine. Formation of this species is kinetically favored, but cleavage of the N-N bond under the reaction conditions leads to selective formation of the thermodynamically favored cross-coupling product.
Synthetic organic chemists have a long-standing appreciation for transition metal cyclopentadienyl complexes, of which many have been used as catalysts for organic transformations. Much less well known are the contributions of the benzo-fuzed relative of the cyclopentadienyl ligand, the indenyl ligand, whose unique properties have in many cases imparted differential reactivity in catalytic processes toward the synthesis of small molecules. In this review, we will present examples of indenylmetal complexes in catalysis and compare their reactivity to their cyclopentadienyl analogues, wherever possible.
Enantiomerically enriched [3.1.0] bicycles containing vicinal quaternary centers were synthesized from [1,6]-enynes using a cyclopentadienylruthenium catalyst containing a tethered chiral sulfoxide. The reaction was complicated by the fact that the substrates contained a racemic propargyl alcohol that could affect the selectivity of the process. Nonetheless, high levels of enantioinduction were observed, despite complications arising from the use of racemic substrates. Mechanistic studies showed that while the utilization of either enantiomer of the propargyl alcohol led to high product enantiomeric ratios when the reaction was conducted in acetone, a significant matched/mismatched effect was observed in tetrahydrofuran.
Copper salts and
organic aminoxyls, such as TEMPO (2,2,6,6-tetramethylpiperidine-N-oxyl), are versatile catalysts for aerobic alcohol oxidation.
Previous reports in the literature contain conflicting proposals concerning
the redox interactions that take place between copper(I) and copper(II)
salts with the aminoxyl and hydroxylamine species, TEMPO and TEMPOH,
respectively. Here, we reinvestigate these reactions in an effort
to resolve the conflicting claims in the literature. Under anaerobic
conditions, CuIIX2 salts [X = acetate (OAc),
trifluoroacetate (TFA), and triflate (OTf)] are shown to promote the
rapid proton-coupled oxidation of TEMPOH to TEMPO: CuIIX2 + TEMPOH → CuIX + TEMPO + HX. In
the reaction with acetate, however, slow reoxidation of CuIOAc occurs. This process requires both TEMPO and HOAc and coincides
with the reduction of TEMPO to 2,2,6,6-tetramethylpiperidine.
Analogous reactivity is not observed with trifluoroacetate and triflate
species. Overall, the facility of the proton-coupled oxidation of
TEMPOH by CuII salts suggests that this process could contribute
to catalyst regeneration under aerobic oxidation conditions.
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