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Abstract. NoSQL databases have emerged as a backend to support Big Data applications. NoSQL databases are characterized by horizontal scalability, schema-free data models, and easy cloud deployment. To avoid overprovisioning, it is essential to be able to identify the correct number of nodes required for a specific system before deployment. This paper benchmarks and compares three of the most common NoSQL databases: Cassandra, MongoDB and HBase. We deploy them on the Amazon EC2 cloud platform using different types of virtual machines and cluster sizes to study the effect of different configurations. We then compare the behavior of these systems to high-level queueing network models. Our results show that the models are able to capture the main performance characteristics of the studied databases and form the basis for a capacity planning tool for service providers and service users.

The use of unbiased aliphatic alkene as the coupling partner for C−H olefination continues to be a challenging task. A suitable chelating directing group allowed ortho C−H olefination of benzyl phosphonamide with unactivated aliphatic alkenes. The broad substrate scope with respect to variation of benzyl phosphonamides and aliphatic alkenes as well as examples of sequential hetero-bis-olefinations offer diversity along with excellent linear/branch selectivity.

A silver(I) catalyzed regioselective trifluoromethylation of allenes using Langlois's salt (NaOSOCF3) is demonstrated. This transformation enables direct expedient access to α‐trifluoromethylated acroleins, which are valuable synthons for a number of pharmaceuticals and agrochemicals containing vinyl‐CF3 moieties. Versatility of this trifluoromethylation method has been established with good yield and excellent regioselectivity. Preliminary experiments and computational studies were carried out to elucidate the mechanistic insight of this protocol.

A regioselective meta-C–H activation strategy for benzophenone was successfully developed by overriding the inherent ketone-directed ortho-selectivity.