Total Synthesis of Resolvin T4

A total synthesis of resolvin T4 was achieved by connecting three intermediates by Wittig reactions. The enal in the C1–C10 part was constructed through reduction of a propargylic alcohol with Red-Al followed by oxidation. The enal moiety in the C11–C16 part was synthesized by a ring-opening reaction of a silyl epoxide followed by a Peterson elimination. The chiral centers at C7 and C13 were constructed by ruthenium-catalyzed asymmetric transfer hydrogenation.

Vinylidene, allenylidene, cyclic oxycarbene, and η2-alkyne complexes from reactions of (η5-C5Me5)OsCl(PPh3)2 with alkynes and alkynols

Reactions of Cp*OsCl(PPh3)2 (Cp* = pentamethylcyclopentadienyl) with alkynes and alkynols are described. Treatment of Cp*OsCl(PPh3)2 with phenylacetylene and trimethylsilylacetylene gave the vinylidene complexes Cp*OsCl(=C=CHPh)(PPh3) and Cp*OsCl(=C=CH2)(PPh3), respectively. Treatment of Cp*OsCl(PPh3)2 with the internal alkyne dimethyl acetylenedicarboxylate produced the η2-alkyne complex Cp*OsCl(η2-MeO2C≡CCO2Me)(PPh3). Treatment of Cp*OsCl(PPh3)2 with the propargylic alcohol HC≡CC(OH)Ph2 gave the osmium allenylidene complex Cp*OsCl(=C = C=CPh2)(PPh3). The outcomes of the reactions of Cp*OsCl(PPh3)2 with ω-alkynols HC≡C(CH2)nOH are dependent on the length of the -(CH2)n- linker. The reaction with 3-butyn-1-ol produced the cyclic oxycarbene complex Cp*OsCl{=C(CH2)3O}(PPh3) exclusively. The reactions with 4-pentyn-1-ol produced a mixture of the hydroxyalkyl vinylidene complex Cp*OsCl{=C=CH(CH2)3OH}(PPh3) and the cyclic oxycarbene complex Cp*OsCl{=C(CH2)4O}(PPh3) in about 10:1 molar ratio. The reaction with 5-hexyn-1-ol gave exclusively the hydroxyalkyl vinylidene complex Cp*OsCl{=C=CH(CH2)4OH}(PPh3).

Facile Synthesis, Structure and Properties of CO2-sourced Poly(thioether-co-carbonate)s Containing Acetyl Pendants via Thio-Ene Click Polymerization

Herein, we present a facile and effective method for the synthesis of CO2-sourced sequence-controlled poly(thioether-co-carbonate)s via consecutive organocatalyzed carboxylative cyclization of vinyl-functionalized propargylic alcohol with CO2, ring-opening transesterification of the...

Organocatalytic Stereoselective 1,6-Addition of Thiolacetic Acids to Propargylic Indole Imine Methides: Access to Axially Chiral Sulfur-containing Tetrasubstituted Allenes

A chiral phosphoric acid catalyzed enantioselective 1,6-conjugate addition of thiolacetic acid to propargylic indole imine methide in situ formed from α-(3-indolyl) propargylic alcohol has been established, which enables the formation...

One-Pot Synthesis of Tetrasubstituted 2-Aminofurans via Au(I)-Catalyzed Cascade Reaction of Ynamides with Propargylic Alcohols

One-pot synthesis of fully substituted 2-aminofurans via a Au(I)-catalyzed cascade reaction of ynamides and propargylic alcohol was realized. Hydroalkoxylation of ynamide with propargylic alcohol, Saucy-Marbet rearrangement, and cyclization of the...