60512-54-1Relevant articles and documents
Radical Carbonyl Propargylation by Dual Catalysis
Huang, Huan-Ming,Bellotti, Peter,Daniliuc, Constantin G.,Glorius, Frank
supporting information, p. 2464 - 2471 (2020/12/07)
Carbonyl propargylation has been established as a valuable tool in the realm of carbon–carbon bond forming reactions. The 1,3-enyne moiety has been recognized as an alternative pronucleophile in the above transformation through an ionic mechanism. Herein, we report for the first time, the radical carbonyl propargylation through dual chromium/photoredox catalysis. A library of valuable homopropargylic alcohols bearing all-carbon quaternary centers could be obtained by a catalytic radical three-component coupling of 1,3-enynes, aldehydes and suitable radical precursors (41 examples). This redox-neutral multi-component reaction occurs under very mild conditions and shows high functional group tolerance. Remarkably, bench-stable, non-toxic, and inexpensive CrCl3 could be employed as a chromium source. Preliminary mechanistic investigations suggest a radical-polar crossover mechanism, which offers a complementary and novel approach towards the preparation of valuable synthetic architectures from simple chemicals.
Cyclization of 2-alkynylallyl alcohols to highly substituted furans by gold(I)-carbene complexes
Hashmi, A. Stephen K.,Rudolph, Matthias,Rominger, Frank
supporting information; experimental part, p. 667 - 671 (2011/03/22)
Various 2-alkynylallyl alcohols were synthesized by a generally applicable Sonogashira coupling protocol. Subsequent gold-catalyzed transformation was investigated. The use of AuI catalysts bearing carbene ligands, of either the N-heterocyclic carbene or nitrogen acyclic carbene type, delivered the desired products with low catalyst loadings and under very mild reaction conditions. A broad array of substrates was tested, including alkyl-, alkenyl-, and aryl-substituted alkynes, as well as substrates with two alkynyl moieties. The methodology turned out to have a broad scope. Secondary allyl alcohols were also tolerated, and the resulting trisubstituted furans could be isolated in high yields. Easily accessible 2-alkynylallyl alcohols were transformed into highly substituted furans under very mild reaction conditions by the use of gold(I)-carbene catalysts. A broad range of substrates could be transformed in high yields and within short reaction times.
