Enantioselective Oxy‐Heck–Matsuda Arylations: Expeditious Synthesis of Dihydrobenzofuran Systems and Total Synthesis of the Neolignan (−)‐Conocarpan. Issue 2 (11th January 2018)

• Record Type: Journal Article
• Authors: Silva, Allan R.; Polo, Ellen C.; Martins, Nelson C.; Correia, Carlos Roque D.
• Is Part Of: Advanced synthesis & catalysis. Volume 360:Issue 2(2018)
• Page Start: 346
• Page End: 365
• Publication Date: 2018-01-11
• Subjects: aryldiazonium salts -- dihydrobenzofurans -- N, N-ligands -- neolignans -- oxy-Heck–Matsuda arylations; Catalysis -- Periodicals; Organic compounds -- Synthesis -- Periodicals; Chemistry -- Periodicals; Chemistry, Technical -- Periodicals; Chemistry -- Periodicals; Catalysis -- Periodicals; Technology, Pharmaceutical -- Periodicals; 547.2
• DOI: 10.1002/adsc.201701278
• Languages: English
• ISSNs: 1615-4150

Abstract

Abstract: This work discloses the first examples of an effective enantioselective oxy‐Heck–Matsuda reaction using a variety of styrenic olefins to generate chiral dihydrobenzofurans. The reaction proceeds in moderate to good yields, with high trans diastereoselectivity (up to 20:1) in enantioselectivities up to 90:10 using the N, N‐ligand pyrimidine‐bisoxazoline (PyriBox). The oxy‐Heck–Matsuda reactions were carried out under mild conditions and rather low catalyst loadings. The feasibility and practicality of the process is demonstrated by a concise total synthesis of the neolignan (−)‐conocarpan. X‐ray diffraction of an advanced brominated intermediate in the route to (−)‐conocarpan has allowed the unequivocal assignment of the absolute stereochemistry of the oxy‐Heck–Matsuda aryldihydrobenzofuran products. A rationale for the mechanism operating in these enantioselective oxy‐Heck–Matsuda reactions is also presented. Abstract :