Transition‐Metal‐Catalyzed Rearrangement of Allenyl Sulfides: A Route to Furan Derivatives

Synthesis of furan from allenic sulfide derivatives

“…We have continued to study this reaction from more easily available starting materials, the α-diazo carbonyl compounds and propargyl sulfides, which are catalyzed by two catalysts successively or only by one catalyst to form furan derivatives through two sequential rearrangements (Scheme 2) [18] .…”

“…The preparation of β-hydroxyl allenic sulfides 1a-k β-Ester allenic sulfides were prepared directly by the Rh(Ⅱ)-or Cu(Ⅰ)-catalyzed reaction of the α-diazo carbonyl compounds with propargyl sulfides through metal carbene-ylide- [2,3] σ rearrangement pathway [18][19][20] . Further reduction could transform the corresponding esters to a series of β-hydroxyl allenic sulfides 1a-k conveniently.…”

Metal-catalyzed Furan Synthesis. A Review

“…73 The proposed mechanism involves cyclization of the sulfur onto the allene followed by ring opening to generate a Ru-alkylidene species, which re-cyclizes and then loses the metal to form the furan. The authors went on to show that the synthesis of the allenyl sulfide substrates and the subsequent cycloisomerization can both be catalyzed in a one-pot tandem process.…”

Ru(II)-Catalyzed rearrangement of 2-aryl-2-(phenylthio)penta-3,4-dienyl 2,2,2-trichloroacetimidates

“…We have recently reported the reaction of [RuCl 2 (p-cymene)] 2 -or PtCl 2 -catalyzed rearrangement of b-carbonyl allenic sulfides which afford furan products in high yields [31]. The reaction proceeds through 1,4-migration of the sulfanyl group and presumably involves a metal carbene intermediate which is trapped intramolecularly by a carbonyl group (Scheme 1).…”