Fusarium is an emerging opportunistic fungal pathogen that causes local or systemic infections. The successful use of a therapeutic drug or combination antifungal therapies against Fusarium spp. are compromised because reports of multidrug resistance are currently frequent. Thus, the development of new antifungal capable of combating multidrug‐resistant Fusarium strains becomes necessary. This study presents the synthesis of seven new allylic selenocyanates and their screening against Fusarium spp. Minimum inhibitory concentrations (MICs) of these compounds ranged from 4 to 64 μg mL−1, with the mechanism of action being related to fungal cell membrane disruption. Specific structural changes, such as widespread thinning along the hyphae, were observed by scanning electron microscopy. The effect of selenocyanates on cell viability and genotoxicity are concentration dependent, however they did not cause mutagenicity in human cells. Five selenocyanates were identified as nonirritant by the ex‐vivo HET‐CAM (Hen′s Egg Test‐Chorioallantoic Membrane) method. Allylic selenocyanates represents a promising alternative in the treatment and prevention of fusariosis.

The one-pot microwave-assisted synthesis of a series of αylidene δ-lactones from (Z)-2-(bromomethyl)-2-alkenoates (derived from Morita-Baylis-Hillman reaction) in an aqueous environment is reported. The protocol includes regioselective base-mediated allylation of ethyl acetoacetate with (Z)-2-(bromomethyl)-2-alkenoates followed by decarboxylative hydrolysis, carbonyl reduction of the keto carboxylate intermediate, and acid-mediated cyclization of the resulting δ-hydroxy acid to furnish the α-ylidene δ-lactones with good overall yields. The synthesis was also performed in the stepwise mode, which allowed the isolation and full characterization of each intermediate involved in the one-pot method. The main features of this efficient transformation include the fast reaction rates, the use of a benign aqueous medium, the use of inexpensive and readily available reagents, the production of nearly innocuous residues, and the requirement for a single work-up and purification stage at the end of the process.

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The synthesis of novel allylic α‐diazo carbonyl compounds was achieved through a one‐pot strategy involving base‐catalyzed allylation of 1,3‐dicarbonyls with readily available allylic bromides followed by the deacylative diazo transfer reaction. Besides the broad substrate scope related to this method, other relevant features include the use of simple and inexpensive reagents, non‐toxic solvents and mild reaction conditions. The synthetic utility of these α‐diazo‐γ,δ‐unsaturated esters was further demonstrated through rhodium‐catalyzed transformations, where the type of product formed is dependent on both the substrate and catalyst employed. Thus, treating α‐diazo‐γ,δ‐unsaturated esters with catalytic Rh2(pfb)4 in acetonitrile under reflux resulted in a diastereoselective β‐hydride migration to give 2Z,4E‐dienes in good yields. On the other hand, the combination of Rh2(OAc)4 as the catalyst in toluene under reflux for 10 min led the aryl‐substituted diazo compounds to a regioselective intramolecular Buchner reaction to furnish 5,7‐fused bicyclic tetraenes in high yields, while the alkyl‐substituted analogues undergo intramolecular C–H insertion to give functionalized cyclopentenes of anti‐configuration.

Candida is a genus that causes the highest number of fungal infections on people around the world, responsible for high mortality rates in critical and immunocompromised patients. Even though several antifungals are commercially available, most of these have side effects or are only available for intravenous administration. In view of this aspect, the susceptibility of twelve allylic selenocyanate (AS) compounds, five of them novel, were tested against 36 Candida strains. The AS were active for all Candida strains reaching minimal inhibitory concentrations (MIC) in the order of ng mL−1 (0.39–50 μg mL−1). The sorbitol and ergosterol assay show that these compounds do not act on the cell wall and fungal membrane, suggesting a different mechanism of action. Cytotoxicity and irritability tests showed that only three molecules already studied (2 b, 2 j and 2 i) for this series manifested damage to the leukocyte cell and chorioallantoic membrane, but at higher concentrations than the MICs. Considering the susceptibility results and parameters of Lipinski, molecules 2 c (0.39–12.5 μg mL−1) and 2 d (0.78–6.2 μg mL−1) look promising for the development of a new antifungal agent against Candida infections.