Synthesis of 8-Aza- and 8-Oxabicyclo[3.2.1]octanes via [3+2]-Cycloadditions of cyclopropanated Furan and Pyrrole Derivatives

The present thesis deals with the synthesis of 8-aza- and 8-oxabicyclo[3.2.1]octanes via a microwave-assisted, stereoselective 6π-electrocyclic ring-opening / [3+2]-cycloaddition cascade of monocyclopropanated pyrrole and furan derivatives with electron poor dipolarophiles. The key step of this transformation is a thermally induced selective cleavage of the non-activated, endocyclic C1-C3 cyclopropane bond in 2-aza- or 2-oxabicyclo[3.1.0]-hex-3-enes, resulting in 1,3-dipoles which can be trapped with suitable dipolarophiles. Starting from pyrroles or furans, 8-aza- and 8-oxabicyclo[3.2.1]octanes are accessible in two steps (cyclopropanation/cycloaddition) in diastereo- and enantioselective pure form, being versatile building blocks for the synthesis of pharmaceutically relevant targets. Various postfunctionalizations of the scaffolds obtained are possible, allowing their further diversifications

Stereoselective Synthesis of Tropanes via a Retro-6 p Electrocyclic Ring-Opening / Huisgen [3+2]-Cycloaddition Cascade of Monocyclopropanated Heterocycles. Stereoselektive Synthese von Tropanen über eine 6π-elektrocyclische Ringöffnung/ Huisgen-[3+2]-Cycloadditionskaskade von monocyclopropanierten Heterocyclen

The synthesis of tropanes via a microwave-assisted, stereoselective 6 pi-electrocyclic ring-opening/ Huisgen [3+2]-cycloaddition cascade of cyclopropanated pyrrole and furan derivatives with electron-deficient dipolarophiles is demonstrated. Starting from furans or pyrroles, 8-aza- and 8-oxabicyclo[3.2.1]octanes are accessible in two steps in dia- and enantioselective pure form, being versatile building blocks for the synthesis of pharmaceutically relevant targets, especially for new cocaine analogues bearing various substituents at the C-6/C-7 positions of the tropane ring system. Moreover, the 2-azabicyclo[2.2.2]octane core (isoquinuclidines), being prominently represented in many natural and pharmaceutical products, is accessible via this approach

Badges to Acknowledge Open Practices: A Simple, Low-Cost, Effective Method for Increasing Transparency

Beginning January 2014, Psychological Science gave authors the opportunity to signal open data and materials if they qualified for badges that accompanied published articles. Before badges, less than 3% of Psychological Science articles reported open data. After badges, 23% reported open data, with an accelerating trend; 39% reported open data in the first half of 2015, an increase of more than an order of magnitude from baseline. There was no change over time in the low rates of data sharing among comparison journals. Moreover, reporting openness does not guarantee openness. When badges were earned, reportedly available data were more likely to be actually available, correct, usable, and complete than when badges were not earned. Open materials also increased to a weaker degree, and there was more variability among comparison journals. Badges are simple, effective signals to promote open practices and improve preservation of data and materials by using independent repositories

Badges to Acknowledge Open Practices: A Simple, Low-Cost, Effective Method for Increasing Transparency

Beginning January 2014, Psychological Science gave authors the opportunity to signal open data and materials if they qualified for badges that accompanied published articles. Before badges, less than 3% of Psychological Science articles reported open data. After badges, 23% reported open data, with an accelerating trend; 39% reported open data in the first half of 2015, an increase of more than an order of magnitude from baseline. There was no change over time in the low rates of data sharing among comparison journals. Moreover, reporting openness does not guarantee openness. When badges were earned, reportedly available data were more likely to be actually available, correct, usable, and complete than when badges were not earned. Open materials also increased to a weaker degree, and there was more variability among comparison journals. Badges are simple, effective signals to promote open practices and improve preservation of data and materials by using independent repositories