Hydrogenation Processes in the Synthesis of Perfumery Ingredients

Abstract

Homogeneous catalytic hydrogenation has played an important role in the development of modern organic synthesis. Indeed, the discovery of highly regio- and stereoselective catalysts for C=C and C=O bonds reductions has allowed the efficient synthesis of optically active compounds. As the fragrance industry has turned to synthetic ingredients to fulfill the need for novel, cost-effective, and environment-friendly products, the use of catalytic processes are more and more in demand. In this Account, we thus highlight the application of catalytic hydrogenation in the synthesis of fragrance ingredients.

Phosphite‐thioether/selenoether Ligands from Carbohydrates: An Easily Accessible Ligand Library for the Asymmetric Hydrogenation of Functionalized and Unfunctionalized Olefins

“…Ligands L1-L24 a-g have been prepared from hydroxyl-thioether/selenoether compounds 5-10, 12-14, [17][18][19]21,[26][27][28][29][30][31][32][33]35,38 and 41 (Schemes 1 and 2). These compounds were easily synthesized on a multigram scale by highly efficient methods from compounds 1 [15] and 2, [16] which are derived from cheap natural L-(+)-tartaric acid (Scheme 1) and D-(+)-mannitol (Scheme 2), respectively.…”

“…The efficient hydrogenation of S4-S16 is important because the resulting products are key units in relevant molecules. [21] Some selected results are shown in Table 2 (for complete set of results see Supporting Information).…”

Chemoselective Hydrogenation of Cinnamaldehyde over a Pt-Lewis Acid Collaborative Catalyst under Ambient Conditions

“…3 In this context, selective hydrogenation of α,β-unsaturated aldehydes to their corresponding semihydrogenated products has attracted considerable attention in both fundamental research and industrial scales, due to its wide application in the syntheses of many important chemicals and intermediates. 4,5 Cinnamaldehyde, a typical α,β-unsaturated aldehyde, has two distinct competing sites of hydrogenation: a CO bond and a conjugated CC group, which generally leads to a complex reaction network involving a parallel and consecutive reduction at different functional groups ( Figure 1). For instance, cinnamyl alcohol from the CO bond hydrogenation and hydrocinnamaldehyde from the conjugated CC bond hydrogenation are both widely used in pharmaceuticals, perfumes, and flavors.…”

Cyanid‐freie und breit anwendbare enantioselektive Syntheseplattform für chirale Nitrile durch einen biokatalytischen Zugang

“…Um diese Hypothese der "privilegierten Substratstruktur" zu überprüfen und unsere Kenntnisse über den Einfluss von Substituenten am aromatischen Ring zu vertiefen, untersuchten wir Br-, Cl-und F-substituierte 2-Aryl-2-methylacetaldoxime (11)(12)(13)(14)(15)(16)(17) Reaktionszeit;N r. 9und 10:4hReaktionszeit;mit "-" bezeichnete Einträge bei den Umsätzen bedeuten, dass in diesen Fällen kein Produktsignalb eobachtet wurde, entsprechende inem Umsatz unterhalb der Nachweisgrenze (< 2%).…”