Synthesis of the C9-C25 Subunit of Spirastrellolide B.

The synthesis of the C9-C25 subunit of the marine natural product spirastrellolide B is reported. The key synthetic features included the union of the two key fragments 5 and 6 via a Suzuki-Miyaura coupling reaction and a late-stage, one-pot sequential deprotection/cascade Achmatowicz rearrangement-spiroketalization to install the key spirocyclic intermediate present in the C9-C25 fragment of spirastrellolide B. The synthesis of the C9-C16 fragment 6 was accomplished via a phosphate tether mediated ring-closing metathesis (RCM), a subsequent hydroboration-oxidation protocol, followed by other stereoselective transformations in a facile manner.

Modular Synthesis of Novel Macrocycles Bearing α,β-Unsaturated Chemotypes through a Series of One-Pot, Sequential Protocols.

A series of one-pot, sequential protocols was developed for the synthesis of novel macrocycles bearing α,β-unsaturated chemotypes. The method highlights a phosphate tether-mediated approach to establish asymmetry, and consecutive one-pot, sequential processes to access the macrocycles with minimal purification procedures. This library amenable strategy provided diverse macrocycles containing α,β-unsaturated carbon-, sulfur-, or phosphorus-based warheads.

A Pot-Economical Approach to the Total Synthesis of Sch-725674.

A pot-economical total synthesis of antifungal Sch-725674, 1, is reported. The approach takes advantage of a number of one-pot, sequential transformations, including a phosphate tether-mediated one-pot, sequential RCM/CM/chemoselective hydrogenation protocol, a one-pot tosylation/acrylation sequence, and a one-pot, sequential Finkelstein reaction/Boord olefination/acetonide deprotection procedure to streamline the synthesis route by reducing isolation and purification procedures, thus saving time. Overall, an asymmetric route has been developed that is efficiently accomplished in seven pots from phosphate (S,S)-triene and with minimal purification.

5-epi-Torrubiellutin C shows antiproliferative activity on DU145 prostate cancer cells through inactivation of the AKT/mTOR pathway.

Cell-based assays for evaluation of the anticancer potential of a focused small molecule library have identified a few potential hit molecules. Among the hits identified, Torrubiellutins (3a) showed good anticancer potential across the cells used in screening assays. Torrubiellutins are isolated from fungal insects Torrubiella luteorostrata and diverse pharmacological effects for these have been reported.

Synthesis of 1,4,5-trisubstituted 1,2,3-triazoles amicable for automation.

A three-component 3+2 cycloaddition reaction followed by Suzuki coupling reaction was carried out to synthesize a library of compounds using automation (parallel synthesizer). Scaffolds that are unexplored in literature were used for the synthesis of library. The iodo-triazoles formed by 3+2 cycloaddition reaction were coupled with boronic acids to get tri-substituted triazoles.

Toward tubulysin: gram-scale synthesis of tubuvaline-tubuphenylalanine fragment.

A practical and stereoselective synthesis of the tubuvaline-tubuphenylalanine (Tuv-Tup) fragment of tubulysin is achieved involving the opening of aziridine, crucial MacMillan alpha-hydroxylation on both fragments, and an epoxide-opening reaction.