An expeditious, high-yielding synthesis of rare α-fluoroepoxides and α-fluoroaziridines through the addition of the unkown fluoroiodomethyllithium (LiCHIF)formed via deprotonation the commercially available fluoroiodomethane with a lithium amide baseto carbonyl-like compounds is documented. The ring-closure reactions, leading to α-fluorinated three-membered heterocycles, rely on the diversely reactive C–I and C–F bonds. Excellent chemoselectivity was observed in the presence of highly sensitive functionalitiesaldehyde, ketone, nitrile, alkenewhich remained untouched during the homologation sequence.

Homologation strategies provide highly versatile tools in organic synthesis for the introduction of a CH2 group into a given carbon skeleton. The operation can result in diverse structural motifs by tuning of the reaction conditions and the nature of the homologating agent. In this Account, concisely contextualizing our work with lithium carbenoids (LiCH2X, LiCHXY etc) for homologating carbon-centered electrophiles, we focus on the assembly of three-membered cycles featuring fluorinated substituents. Two illustrative case studies are considered: (1) the development and employment of fluorinated carbenoids en route to rare α-fluoroepoxides and aziridines, and (2) the installation of up to halomethylenic groups on trifluoroimidoylacetyl chlorides (TFAICs) for preparing CF3-containing halo- and halomethylaziridines. Collectively, we demonstrate that the initial homologation event generated by the installation of the carbenoid, upon modulation of the conditions, serves as a tool for creating fluorinated building blocks in a single operation.

A sequential C1-homologation – nucleophilic substitution tactic is presented for preparing rare unsymmetrical dithioacetals. The judicious selection of thiosulfonates as convenient sulfur electrophilic sources – upon the homologation event conducting...

The necessity of more sustainable conditions that follow the twelve principles of Green Chemistry have pushed researchers to the development of novel reagents, catalysts and solvents for greener asymmetric methodologies. Solvents are in general a fundamental part for developing organic processes, as well as for the separation and purification of the reaction products. By this reason, in the last years, the application of the so-called green solvents has emerged as a useful alternative to the classical organic solvents. These solvents must present some properties, such as a low vapor pressure and toxicity, high boiling point and biodegradability, and must be obtained from renewable sources. In the present revision, the recent application of these biobased solvents in the synthesis of optically active compounds employing different catalytic methodologies, including biocatalysis, organocatalysis and metal catalysis, will be analyzed to provide a novel tool for carrying out more ecofriendly organic processes.

Lithium monohalocarbenoids are useful synthons for conducting C1-homologations, although their high tendency to suffer degradative α-elimination, leading to a lithium halide and a free carbene, is the main drawback for...

A conceptually intuitive synthesis of oxothioacetals is reported starting from thiosulfonates as electrophilic sulfur donors. The installation of a reactive CH 2 Cl motif with a homologating carbenoid reagent, followed by the immediate nucleophilic displacement with alcoholic groups [(hetero)-aromatic, aliphatic] offer a convenient access to the title compounds. Genuine chemoselectivity is uniformly observed in the case of multi-functionalized systems.

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