Tailored Palladium Catalysts for Selective Synthesis of Conjugated Enynes by Monocarbonylation of 1,3‐Diynes

Abstract

For the first time, the monoalkoxycarbonylation of easily available 1,3‐diynes to give synthetically useful conjugated enynes has been realized. Key to success was the design and utilization of the new ligand 2,2′‐bis(tert‐butyl(pyridin‐2‐yl)phosphanyl)‐1,1′‐binaphthalene (Neolephos), which permits the palladium‐catalyzed selective carbonylation under mild conditions, providing a general preparation of functionalized 1,3‐enynes in good‐to‐high yields with excellent chemoselectivities. Synthetic applications that showcase the possibilities of this novel methodology include an efficient one‐pot synthesis of 4‐aryl‐4H‐pyrans as well as the rapid construction of various heterocyclic, bicyclic, and polycyclic compounds.

Divergent Functionalization of Styrenes via Radical/Polar Crossover with CO2 and Sodium Sulfinates

“…Due to the aforementioned wide applicability of α‐aryl‐acrylates in synthetic organic chemistry and polymer science, and the lack of synthetic methodologies employing styrenes and CO 2 as building blocks, [67–73] we envisioned adapting the reaction conditions of entry 6, in order to explore the leaving group ability of the sulfone moiety for the easy generation of α‐aryl‐acrylates. Therefore, carrying out the photocatalytic protocol in the presence of 1 equiv.…”

Pd‐Catalyzed Tandem Pathway for Stereoselective Synthesis of (E)‐1,3‐Enyne from β‐Nitroalkenes by Using a Sacrificial Directing Group

“…Consequently, significant research have been devoted for the efficient development of conjugated 1,3‐enynes. Classically, Wittig and Horner‐Wadsworth‐Emmons (HWE) olefination (Figure 1A–a), Pd/Cu‐catalyzed Sonogashira as well as Suzuki–Miyaura cross‐coupling reactions (Figure 1A–b) serve as de novo construction of 1,3‐enynes [12–23] . Additionally, transition metal (Rh, Ru, Pd, etc .)…”

A general strategy for the synthesis of α-trifluoromethyl- and α-perfluoroalkyl-β-lactams via palladium-catalyzed carbonylation

“…Based on our long-standing interest in carbonylation reactions 22 and inspired by palladium-catalyzed three component coupling reactions, 23 we got the idea to build up the central 4-membered ring of α-fluoroalkyl-β-lactams by a novel palladium-catalyzed aminocarbonylation of α-halo-α-fluoroalkylolefins, anilines and CO ( Scheme 1 ). At this point, it is worthwhile mentioning that transition metal-catalyzed carbonylation reactions are not only of value for a variety of organic syntheses, but can be easily upscaled as shown by the industrial production of many fine and even bulk chemicals.…”