Solid-Supported Odorless Reagents for the Dithioacetalization of Aldehydes and Ketones

Thioacetalation and Multi-Component Thiomethylative Friedel-Crafts Arylation Using BF3SMe2

Herein, a method for thioacetalation using BF₃SMe₂ is presented. The method allows for convenient and odor-free transformation of aldehydes to methyl-dithioacetals, a simple but sparsely reported structural moiety, in good yields with a diverse set of aromatic aldehydes. In addition, a thiomethylative Friedel-Crafts reaction was discovered, affording thiomethylated diarylmethanes in good to excellent yields. The resulting diarylmethane core is of interest as it is found in many biologically active compounds, and its utility is further demonstrated as a novel precursor to unsymmetrical triarylmethanes. This work also highlights the usefulness and the synthetic capabilities of the readily available reagent BF₃SMe₂ beyond its reactivity profile as a dealkylation reagent.

NFDI4Chem - Towards a National Research Data Infrastructure for Chemistry in Germany

The vision of NFDI4Chem is the digitalisation of all key steps in chemical research to support scientists in their efforts to collect, store, process, analyse, disclose and re-use research data. Measures to promote Open Science and Research Data Management (RDM) in agreement with the FAIR data principles are fundamental aims of NFDI4Chem to serve the chemistry community with a holistic concept for access to research data. To this end, the overarching objective is the development and maintenance of a national research data infrastructure for the research domain of chemistry in Germany, and to enable innovative and easy to use services and novel scientific approaches based on re-use of research data. NFDI4Chem intends to represent all disciplines of chemistry in academia. We aim to collaborate closely with thematically related consortia. In the initial phase, NFDI4Chem focuses on data related to molecules and reactions including data for their experimental and theoretical characterisation.

This overarching goal is achieved by working towards a number of key objectives:

Key Objective 1: Establish a virtual environment of federated repositories for storing, disclosing, searching and re-using research data across distributed data sources. Connect existing data repositories and, based on a requirements analysis, establish domain-specific research data repositories for the national research community, and link them to international repositories.

Key Objective 2: Initiate international community processes to establish minimum information (MI) standards for data and machine-readable metadata as well as open data standards in key areas of chemistry. Identify and recommend open data standards in key areas of chemistry, in order to support the FAIR principles for research data. Finally, develop standards, if there is a lack.

Key Objective 3: Foster cultural and digital change towards Smart Laboratory Environments by promoting the use of digital tools in all stages of research and promote subsequent Research Data Management (RDM) at all levels of academia, beginning in undergraduate studies curricula.

Key Objective 4: Engage with the chemistry community in Germany through a wide range of measures to create awareness for and foster the adoption of FAIR data management. Initiate processes to integrate RDM and data science into curricula. Offer a wide range of training opportunities for researchers.

Key Objective 5: Explore synergies with other consortia and promote cross-cutting development within the NFDI.

Key Objective 6: Provide a legally reliable framework of policies and guidelines for FAIR and open RDM.

Addition of dithi(ol)anylium tetrafluoroborates to α,β-unsaturated ketones

In the presented study, dithi(ol)anylium tetrafluoroborates are added to α,β-unsaturated ketones in a Michael-type reaction yielding diverse substituted ketene diothi(ol)anes. The reactions proceed at room temperature in 1 or 13 h without the need of further additives. The presented procedure is in particular useful for dithi(ol)anylium tetrafluoroborates without electron-withdrawing groups in α-position. This is advantageous with respect to previous approaches, which were limited to the use of ketene dithioacetals substituted with electron-withdrawing groups. Aiming for the systematic investigation of possible steric and electronic influences on the outcome of the reaction, various combinations of electrophiles and nucleophiles were used and the results of the reactions were compared based on the type of the used dithioacetal. The scope of the presented procedure is shown with four additional transformations including the use of additional electrophiles and nucleophiles, the use of a chiral auxiliary and subsequent reduction of selected products. Additionally, we extended the reaction to the synthesis of diene dithiolanes by addition of an ynone to α-alkyl or aryl-substitued dithiolanylium TFBs.

Alcohol-mediated direct dithioacetalization of alkynes with 2-chloro-1,3-dithiane for the synthesis of Markovnikov dithianes

An alcohol-mediated dithioacetalization process that gains direct access to the corresponding Markovnikov-selective 1,3-dithianes using unactivated alkynes and nonthiolic/odorless 2-chloro-1,3-dithiane in a highly efficient manner has been developed. This methodology has the advantage of having mild reaction conditions, and the dithioacetalization process gives good to excellent yields with high Markovnikov-selectivity.

Aerobic copper-catalyzed oxidative [6C+1C] annulation: an efficient route to seven-membered carbocycles

A copper-catalyzed aerobic tandem Michael addition–intramolecular radical cyclization–benzyl C(sp³)–H bond oxidation reaction of dicinnamoyl ketene dithioacetals and ethyl cyanoacetate was developed for the diastereoselective synthesis of seven-membered carbocycles.