Efficient One‐Pot Synthesis of Multi‐Substituted Dihydrofurans by Ruthenium(II)‐Catalyzed [3+2] Cycloaddition of Cyclic or Acyclic Diazodicarbonyl Compounds with Olefins

Abstract

Ruthenium(II)‐phosphine complexes‐catalyzed [3+2] cycloadditions were conducted to synthesize a variety of dihydrofurans by reactions of cyclic or acyclic diazodicarbonyl compounds with olefins. This method represents a direct and efficient one‐pot synthesis for multi‐substituted dihydrofurans under mild reaction conditions with an excellent regioselectivity. Furthermore, to reduce reaction times and increase yields of dihydrofurans, microwave‐assisted tris(triphenylphosphine)ruthenium(II) chloride/ 1‐butyl‐3‐methylimidazolium tetrafluoroborate {Ru(PPh3)3Cl2/[Bmim]BF4}‐catalyzed reactions were also developed. The synthesized dihydrofurans can be readily converted into biologically interesting tetrahydroindoles.magnified image

Novel one-pot synthesis of diverse γ,δ-unsaturated β-ketoesters by thermal cascade reactions of diazodicarbonyl compounds and enol ethers: transformation into substituted 3,5-diketoesters

“…19 In this case, only dihydrofuran 2a was produced in high yields and no other product associated with the Wolff rearrangement was obtained.…”

$$\hbox {Re}_{2}\hbox {O}_{7}$$ Re 2 O 7 -catalyzed formal [3 + 2] cycloaddition for diverse naphtho[1,2-b]furan-3-carboxamides and their biological evaluation

“…In particular, there are no reports of a biological study of naphtho [1,2-b]furan-3-carboxamides. Accordingly, as part of an our ongoing study of the synthesis of bio-active heterocycles [20,[37][38][39][40][41][42][43] and the search for novel anti-tyrosinase, antioxidant, and antibacterial agents [20,21,[44][45][46], diverse naphtho[1,2-b]furan-3-carboxamide derivatives were synthesized starting from 1,4-dihydroxy-2-naphthoic acid via methylation, oxidation, followed by Re 2 O 7 -catalyzed cascade formal [3+2] cycloaddition processes. The synthesized naphtho [1,2-b]furan-3-carboxamides were then evaluated for their anti-tyrosinase, antioxidant, and antibacterial activities.…”

Regioselective Synthesis of Highly Functionalized Furans Through the RuII‐Catalyzed [3+2] Cycloaddition of Diazodicarbonyl Compounds

“…We have reported on the decomposition of cyclic diazodicarbonyl compounds with various substrates as a powerful means for synthesizing heterocycles and novel organic compounds 11. Recently we reported on Ru II ‐catalyzed reactions between diazodicarbonyl compounds and olefins to afford multisubstituted dihydrofurans 12. As part of our ongoing studies on the transition‐metal‐catalyzed transformations of diazodicarbonyl compounds to provide novel molecules, we became interested in the Ru II ‐catalyzed cycloaddition of diazodicarbonyl compounds to terminal alkynes.…”