Rh-Catalyzed [5+1] and [4+1] Cycloaddition Reactions of 1,4-Enyne Esters with CO: A Shortcut to Functionalized Resorcinols and Cyclopentenones

• Published in: Chemistry : a European journal Vol. 18; no. 23; pp. 7243 - 7247
• Main Authors: Fukuyama, Takahide, Ohta, Yuko, Brancour, Célia, Miyagawa, Kazusa, Ryu, Ilhyong, Dhimane, Anne-Lise, Fensterbank, Louis, Malacria, Max
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 04.06.2012; WILEY‐VCH Verlag; Wiley; Wiley Subscription Services, Inc; Wiley-VCH Verlag
• Subjects: 1,4‐enyne esters; 4-enyne esters; acyloxy migration; Alkynes; carbonylation; Carbonyls; Chemical Sciences; Chemistry; Chemistry, Multidisciplinary; Cycloaddition; Derivatives; Esters; Migration; Organic chemistry; Physical Sciences; Rhodium; Science & Technology; Terminals; 4-enyne esters; PROPARGYLIC ESTERS; GOLD CATALYSIS; COMPLEXES; KETENE LIGAND; ALKYNES; PHENOL DERIVATIVES; 1; cycloaddition; CARBON-MONOXIDE; acyloxy migration; ACETATES; METAL; carbonylation; rhodium
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201200045

We have developed novel Rh‐catalyzed [n+1]‐type cycloadditions of 1,4‐enyne esters, which involve an acyloxy migration as a key step. The efficient preparation of functionalized resorcinols, including biaryl derivatives, from readily available 1,4‐enyne esters and CO was achieved by Rh‐catalyzed [5+1] cycloaddition accompanied by 1,2‐acyloxy migration. When enyne esters had an internal alkyne moiety, the reaction proceeded by a [4+1]‐type cycloaddition involving 1,3‐acyloxy migration, leading to cyclopentenones. Rhodium‐catalyzed carbonylation: New carbonylative cycloaddition reactions of enyne esters have been developed by using a Rh complex as the catalyst. The reaction of terminal alkynes with CO gave functionalized resorcinols by [5+1] cycloaddition acompanied by 1,2‐acyloxy migration, whereas internal alkynes gave cyclopentenones by [4+1] cycloaddition involving 1,3‐acyloxy migration (see scheme).