Total Synthesis of a PPAP, Nemorosonol, Using a Tandem Michael Addition-Intramolecular Aldol Reaction

A strategy for constructing a tricyclo[4.3.1.0^3,7]decane skeleton, which is common to many polycyclic polyprenylated acylphloroglucinols, has been established. The key step was a tandem Michael addition-intramolecular aldol reaction with 3-ethoxy-1-phenyl-2-proyn-1-one, which affords a tricyclo[4.3.1.0^3,7]decane skeleton having a benzoyl group at the C8 position and an appropriate oxygen functional group at the C9 position. This synthetic strategy led to the total synthesis of nemorosonol, which was accomplished in 12 steps from 2-methyl-2-cyclopenten-1-one.

One-Pot Synthesis of Symmetrical and Asymmetrical 3-Amino Diynes via Cu(I)-Catalyzed Reaction of Enaminones with Terminal Alkynes

An economical and efficient protocol for the direct construction of amino skipped diynes through the Cu(I)-catalyzed reaction of enaminones and terminal alkynes has been described. Different kinds of symmetrical and asymmetrical 3-amino diynes could be obtained in up to 83% yield through a one-pot reaction under mild conditions.

Phosphine-Free Ru-Catalyzed Regio- and Stereoselective Addition of Benzoic Acids to Trifluoromethylated Alkynes toward Facile Access to Trifluoromethyl Group-Substituted (E)-Enol Esters

A combination of ruthenium catalyst with silver salt and copper salt was proved to be a highly efficient protocol for the direct addition reaction of benzoic acids with unsymmetrical trifluoromethylated internal alkynes. Diverse trifluoromethyl group-substituted (E)-enol esters were readily obtained for a broad substrate scope in moderate to good yields with excellent regio- and stereoselectivities under mild reaction conditions.

Metal-free synthesis of activated ynesulfonamides and tertiary enesulfonamides

An operationally simple synthesis of activated ynesulfonamides and enesulfonamides is described. Ynesulfonamides can be obtained through reaction of sulfonylamides with activated bromoalkynes and Triton B in a short time at room temperature. Likewise, terminal alkynes react with sulfonylamides to provide enesulfonamides. Z/E enesulfonamides can be transformed exclusively into E enesulfonamides.

Iron-mediated highly diastereoselective allylation of carbonyl compounds with cyclic allylic halides

An efficient iron-mediated highly diastereoselective allylation reaction of carbonyl compounds with cyclic allylic halides using a catalytic amount of bismuth(iii) chloride is reported.