Heterocyclic arynes, or hetarynes, have been studied for over 100 years. However, challenges associated with observing these reactive species, as well as developing synthetically useful methods for ...their generation and trapping, have limited their use. This review provides a brief historical perspective on the field of hetarynes, in addition to a discussion of pyridyne and indolyne methodologies. Moreover, this review highlights the use of pyridynes, indolynes, and related strained intermediates in natural product synthesis.
Heterocyclic arynes have long been targeted as potential tools for the synthesis of substituted heterocycles. Recent advances have led to an improved understanding of the factors that determine ...regioselectivity in reactions of these strained intermediates and, in turn, the aryne distortion model. This paper highlights the use of this predictive model to enable the use of heterocyclic arynes, such as indolynes and pyridynes, in chemical synthesis.
Cnidaria, the sister group to Bilateria, is a highly diverse group of animals in terms of morphology, lifecycles, ecology, and development. How this diversity originated and evolved is not well ...understood because phylogenetic relationships among major cnidarian lineages are unclear, and recent studies present contrasting phylogenetic hypotheses. Here, we use transcriptome data from 15 newly-sequenced species in combination with 26 publicly available genomes and transcriptomes to assess phylogenetic relationships among major cnidarian lineages. Phylogenetic analyses using different partition schemes and models of molecular evolution, as well as topology tests for alternative phylogenetic relationships, support the monophyly of Medusozoa, Anthozoa, Octocorallia, Hydrozoa, and a clade consisting of Staurozoa, Cubozoa, and Scyphozoa. Support for the monophyly of Hexacorallia is weak due to the equivocal position of Ceriantharia. Taken together, these results further resolve deep cnidarian relationships, largely support traditional phylogenetic views on relationships, and provide a historical framework for studying the evolutionary processes involved in one of the most ancient animal radiations.
We investigated the potential of Second Life® (SL), a three‐dimensional (3‐D) virtual world, to enhance undergraduate students’ learning of a vital chemistry concept. A quasi‐experimental ...pre‐posttest control group design was used to conduct the study. A total of 387 participants completed three assignment activities either in SL or using two‐dimensional (2‐D) images. Students were administered an 11‐question chemistry achievement test and two measures of spatial ability (Purdue Visualization of Rotations Test, Card Rotations Test). Although analyses of covariance revealed no statistically significant differences between the two groups as a whole for any of the outcome measures, a subgroup analyses was conducted to decompose the relative impact of 3‐D virtual reality instruction within SL. We found that students classified as having poor spatial ability showed significantly greater improvement in understanding the 3‐D nature of molecules if they did relevant activities in a 3‐D virtual world than those students who only worked with 2‐D images.
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