Synthetic applications of monofluoromethylsulfonium salts

Monofluoromethylsulfonium salts are emerging reagents for the fluoromethylation and fluoromethylenation or fluorometyhlene transfer. This type of reagents display simple approach for introduction of fluoromethyl group into wide range of nucleophiles upon mild basic conditions. Recently, fluoromethylsulfonium salts have been demonstrated to act as a synthetic equivalent of otherwise challenging fluoromethylene synthon. For instance, these reagents can be used for the direct synthesis of monofluoroepoxides and fluorocyclopropanes from activated alkenes via sulfur fluoromethylide intermediate. Sulfonium salts are an alternative, easy-to-handle option to volatile and environmentally concerning freons for achieving monofluorinated compounds. This review focuses on synthetic application of these reagents known to date.

Synthesis of Nitroaromatic Compounds via Three-Component Ring Transformations

1-Methyl-3,5-dinitro-2-pyridone serves as an excellent substrate for nucleophilic-type ring transformation because of the electron deficiency and presence of a good leaving group. In this review, we focus on the three-component ring transformation (TCRT) of dinitropyridone involving a ketone and a nitrogen source. When dinitropyridone is allowed to react with a ketone in the presence of ammonia, TCRT proceeds to afford nitropyridines that are not easily produced by alternative procedures. Ammonium acetate can be used as a nitrogen source instead of ammonia to undergo the TCRT, leading to nitroanilines in addition to nitropyridines. In these reactions, dinitropyridone serves as a safe synthetic equivalent of unstable nitromalonaldehyde.

Seaweeds Compounds: An Ecosustainable Source of Cosmetic Ingredients?

Seaweed-based cosmetics are being gradually used by consumers as a substitute of synthetic equivalent products. These seaweed-based products normally contain purified compounds or extracts with several compounds. Several seaweeds’ molecules already demonstrated a high potential as a cosmetic active ingredient (such as, mycosporine-like amino acids, fucoidan, pigments, phenolic compounds) or as a key element for the products consistency (agar, alginate, carrageenan). Moreover, seaweeds’ compounds present important qualities for cosmetic application, such as low cytotoxicity and low allergens content. However, seaweeds’ biochemical profile can be variable, and the extraction methods can cause the loss of some of the biomolecules. This review gives a general look at the seaweed cosmetics benefits and its current application in the cosmetic industry. Moreover, it focuses on the ecological and sustainable scope of seaweed exploitation to guarantee a safe source of ingredients for the cosmetic industry and consumers.

Stereoselective Synthesis of (4S,5S)-5-Vinyloxazolidin-2-one-4-carboxylate as a β-Vinylserine Synthetic Equivalent by Vinyl Grignard Addition to an N-Tosyl Version of Garner’s Aldehyde

A highly efficient synthesis of a β-vinylserine synthetic equivalent is reported that exploits the stereodirecting effect of the N-toluenesulfonamide in an anti-diastereoselective (8.5:1) vinyl Grignard addition to an analogue of Garner’s aldehyde. Both aryl and alkyl ­Grignards are shown to give increased anti-selectivity compared with N-Boc Garner’s aldehyde.

1,3-Dipolar Cycloadditions Involving Allenes: Synthesis of Five-Membered Rings

The 1,3-dipolar cycloaddition reaction is a powerful and versatile strategy for the synthesis of carbocyclic and heterocyclic five-membered rings. Herein, the most recent developments on the [3+2] cycloaddition reactions using allenes acting either as dipolarophiles or 1,3-dipole precursors, are highlighted. The recent contributions on the phosphine- and transition metal-catalyzed [3+2] annulations involving allenes as substrates are also covered, with the exception of those in which the formation of a 1,3-dipole (or synthetic equivalent) is not invoked. This review summarizes the most relevant research in which allenes are used as building blocks for the construction of structurally diverse five-membered rings via [3+2] annulation reactions.

A synthetic equivalent for unknown 1,3-zwitterions? – A K/OR phosphinidenoid complex with an additional Si–Cl function

Although the chemistry of frustrated Lewis pairs (FLPs) has seen tremendous developments, investigations on anionic, mono-molecular FLPs are still scarce and 1,3-zwitterions are unknown, but a functional K/OR phosphinindenoid complex can be used instead.

The catalytic influence of phosphotungstic acid-functionalized Fe3O4 MNPs blended with TiO2 on the synthesis of novel spiro-acridines and the evaluation of their medicinal potential through molecular docking studies

This manuscript describes an effective and rapid three-component synthesis of a novel series of spiro-acridine derivatives by integrating the pharmacologically dynamic hydantoin–phenytoin as the prime synthetic equivalent.