Good timing in total synthesis: the case of phoslactomycin A

Highly efficient biocatalytic desymmetrization of meso carbocyclic 1,3-dicarboxamides: a versatile route for enantiopure 1,3-disubstituted cyclohexanes and cyclopentanes

Highly efficient biocatalytic desymmetrization of meso carbocyclic 1,3-dicarboxamides to enantiopure 1,3-disubstituted cyclohexanes and cyclopentanes was realized.

Synthetic Strategies Employed for the Construction of Fostriecin and Related Natural Products

Fostriecin and related natural products present a significant challenge for synthetic chemists due to their structural complexity and chemical sensitivity. This review will chronicle the successful efforts of synthetic chemists in the construction of these biologically active molecules. Key carbon-carbon bond forming reactions will be highlighted, as well as the methods used to install the numerous stereocenters present in this class of compounds.

A Highly Convergent Total Synthesis of Leustroducsin B

Leustroducsin B exhibits a large variety of biological activities and unique structural features. An efficient and highly convergent total synthesis of Leustroducsin B was achieved in 17 longest linear and 39 total steps by disconnecting the molecule into three fragments having similar levels of complexity. These pieces were connected via a highly efficient chelate-controlled addition of a vinyl zincate to an α-hydroxy ketone and a silicon-mediated cross-coupling. The stereochemistry of the central and western fragments was set catalytically in high yields and excellent de by a zinc-ProPhenol-catalyzed aldol reaction and a palladium-catalyzed asymmetric allylic alkylation.

A new reactivity mode for the diazo group: diastereoselective 1,3-aminoalkylation reaction of β-amino-α-diazoesters to give triazolines

A novel mode of reactivity for the diazo group, the 1,3-addition of a nucleophile and an electrophile to the diazo group, has been realized in the intramolecular aminoalkylation of β-amino-α-diazoesters to form tetrasubstituted 1,2,3-triazolines. The reaction exhibited a broad scope, good functional group tolerance, and excellent diastereoselectivity. In addition, a new Au-catalyzed intramolecular transannulation reaction of the obtained propargyl triazolines to give pyrroles has been discovered.

Asymmetric synthesis of 3,3,5,5-tetrasubstituted 1,2-dioxolanes: total synthesis of epiplakinic acid F

The first enantioselective total synthesis of epiplakinic acid F (1) was achieved through a pivotal step involving a radical-mediated asymmetric peroxidation of vinylcyclopropanes with molecular oxygen to construct highly substituted 1,2-dioxolanes.

Total synthesis of the postulated structure of fulicineroside

A total synthesis of the proposed structures of fulicineroside and its aglycone fulicinerine is reported. The tetrasubstituted dibenzofuran substructure was accessible either through a Pd-mediated ortho-metalation or by an Ir-catalyzed meta-borylation. The synthesis of the β,β,α-linked trisaccharide consisting of D-olivose, L-rhodinose, and L-rhamnose was challenged by the unprecedented β-linked rhodinose. A Pd-catalyzed β-selective glycosylation of a 4-epi-rhodinose and a subsequent Mitsunobu inversion provided selectively the β-linked L-rhodinose-L-rhamnose disaccharide. Comparison with the reported data for the natural product and the aglycone suggests a misassignment of the structure of the natural product.

Silyl glyoxylates. Conception and realization of flexible conjunctive reagents for multicomponent coupling

This Perspective describes the discovery and development of silyl glyoxylates, a new family of conjunctive reagents for use in multicomponent coupling reactions. The selection of the nucleophilic and electrophilic components determines whether the silyl glyoxylate reagent will function as a synthetic equivalent to the dipolar glycolic acid synthon, the glyoxylate anion synthon, or the α-keto ester homoenolate synthon. The ability to select for any of these reaction modes has translated to excellent structural diversity in the derived three- and four-component coupling adducts. Preliminary findings on the development of catalytic reactions using these reagents are detailed, as are the design and discovery of new reactions directed toward particular functional group arrays embedded within bioactive natural products.

Formal synthesis of leustroducsin B via Reformatsky/Claisen condensation of silyl glyoxylates

A formal synthesis of leustroducsin B has been completed. The synthesis relies upon a recently developed Reformatsky/Claisen condensation of silyl glyoxylates and enantioenriched β-lactones that establishes two of the molecule's three core stereocenters and permits further elaboration to an intermediate in Imanishi's synthesis via reliable chemistry (Prasad reduction, asymmetric pentenylation, Mitsunobu inversion).