RESUMEN
The synthesis of polyketide natural products has been a captivating pursuit in organic chemistry, with a particular focus on selectively introducing 1,3-polyol units. Among these natural products, Marinomycins A-D have garnered substantial interest due to their exceptional structural features and potent cytotoxicity. In this paper, we present a novel approach for synthesising the monomeric counterparts of Marinomycin A and B. Our method employs a previously established iterative cycle in conjunction with a standardised polyketide building block. Through this strategy, we showcase a promising pathway towards total and partial syntheses of these intriguing natural products.
RESUMEN
This brief overview highlights recent progress in the field of cascade reactions that are initiated by the activation of a pi-system using platinum and gold catalysts and that are coupled with a 1,2-alkyl migration step. While the reactions discussed aim to rapidly evolve molecular complexity, they are experimentally straightforward and easy to perform. Primarily guided by the type of 1,2-alkyl migration, methods are categorized as shifts to metal carbenoid centers and pinacol-type rearrangements.
RESUMEN
A combination of gold(I) complexes and amine bases catalyzes the 5-exo-dig cyclization of formyl alkynes. This direct alpha-functionalization of aldehydes with unactivated alkynes does not involve the use of preformed enol equivalents.
RESUMEN
Two protocols for the construction of 4-iodo-3-furanones through a sequence consisting of cyclization and 1,2-migration of 2-alkynyl-2-silyloxy carbonyl compounds were developed. In one, electrophilic cyclization is directly induced by N-iodosuccinimide (NIS). In the second less limited variant, AuCl3 catalyzes the tandem reaction in the presence of NIS to provide highly substituted heterocycles in moderate to excellent yields.
Asunto(s)
Yodo/química , Lactonas/química , Alquilación , Ciclización , Electrones , Lactonas/síntesis química , Estructura MolecularRESUMEN
o-Iodoxybenzoic acid (IBX) was found to mediate the conversion of alpha-alkynyl alcohols into Z-enediones under notably mild conditions via a novel rearrangement mechanism (33-65% yield, 13 examples).