Premium
Gold Catalysis: Domino Reaction of En‐Diynes to Highly Substituted Phenols
Author(s) -
Hashmi A. Stephen K.,
Häffner Tobias,
Rudolph Matthias,
Rominger Frank
Publication year - 2011
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201100305
Subject(s) - chemistry , alkyne , sonogashira coupling , catalysis , furan , moiety , phenols , ketone , carbene , alkyl , cascade reaction , organic chemistry , alcohol , medicinal chemistry , combinatorial chemistry , palladium
Abstract By Sonogashira coupling of 1,7‐heptadiynes and 1,8‐octadiynes with 2‐iodoallyl alcohols, various substrates that bear a 2‐alkynylallyl alcohol moiety tethered to an additional alkyne were prepared in one step. Subjection to nitrogen acyclic carbene (NAC)/gold(I) catalysts delivered highly substituted phenols in an efficient domino reaction. Furan derivatives were formed as intermediates; this was proven by in situ NMR spectroscopy. The uncommon substitution pattern of these furans opens the way for a selective formation of phenols that contain the hydroxyl group in the meta position to the ring junction, which previously was not possible by gold‐catalyzed furan‐yne cyclization. Furthermore, interesting mechanistic insights were obtained by products derived from secondary allyl alcohols. In this case, in addition to the phenolic compounds, a ketone is formed by 1,2‐alkyl shift.