Highly Efficient Organic Reactions “on Water”, “in Water”, and Both

Abstract

Wet, wet, wet: Hydrophobic aldehydes are cleanly oxidized upon stirring with water in air. Addition of hydrophobic isocyanides to aqueous suspensions of such aldehydes results in the formation of Passerini reaction products, with the aldehyde being the source of both carbonyl and ester functions. Partially water‐soluble reagents reacted slower than water‐insoluble ones. Isotope labeling studies show that water participates in these “on water” reactions.

Selective Oxidation of Olefins Catalyzed by Polymer-anchored Nickel(II) Complex in Water Medium

“…1,2 As an alternative solvent, water has paid extraordinary attention because it is not only inexpensive and environmentally benign, but also shows unique reactivity and selectivity. [3][4][5][6] Phase transfer catalysis is becoming an interestingly important technique in organic synthesis. But there is one limitation in this method that many phase transer catalysts promote stable emulsion which render work-up difficult.…”

Electrophilic Activation of Aldehydes “On Water”: A Facile Route to Dipyrromethanes

“…[14] Vigalok and Shapiro reported a general procedure for an aerobic oxidation of aldehydes that takes place on water and its use in the consecutive three-component Passerini reaction [a] Dr. L. Zoli, Prof. P. G. both "on water" and "in water". [15] A possible oxidation mechanism involves the formation of peroxyacid by the interaction of oxygen with the aldehyde. The oxidation of benzaldehyde under the present conditions could be responsible for the final pH of the water phase.…”

Novel peptidomimetic compounds containing redox active chalcogens and quinones as potential anticancer agents

“…As before, the IMCR-based approach turned out to be rather successful for the synthesis of a range of chemically diverse sulfur-, selenium-and tellurium-containing peptidomimetic compounds (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20). These compounds were tested in various cancer cell lines and, in the case of the tellurium compounds, showed considerable activity in many of these cell cultures, possibly by selectively damaging the ER and actin cytoskeleton, delaying the cell cycle and inducing apoptosis.…”

“…As far as the chemical synthesis is concerned, readily available building blocks, including isonitriles were used in the Passerini and Ugi MCRs for the synthesis of 18 peptidomimetic compounds (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) (Figure 2). The individual building blocks used are shown in Figure 1, whereby the isonitriles were prepared in a good yield (up to 82 %) by dehydration of their corresponding formamides using phosphoryl chloride (POCl 3 ).…”

“…This could be attributed to various factors, including the hydrophobic effect and enhanced hydrogen bonding in the transition state. [14][15][16] Additionally, the use of water as solvent permitted the reaction to be conducted rapidly, and as the products are often insoluble in water, it also facilitated their isolation as precipitates. In contrast, low yields and the formation of unfavourable by-products were observed in case of the tellurium-containing isonitrile.…”