Oxidative sulfamidation as a route to N-heterocycles and unsaturated sulfonamides

Oxidative sulfamidation is a promising approach to the synthesis of numerous organic compounds, including N-heterocycles or unsaturated species having the sulfonamide group, which is a key structural motif of synthetic antimicrobial drugs. The formed products can undergo further reactions leading to a wide variety of functionalized sulfonamides. This review summarizes the current state of knowledge on the oxidative reactions of sulfonamides and their derivatives with unsaturated and CH-active compounds with an emphasis on dienes as substrates. This produces a diverse range of compounds possessing sulfonamide function and capable of further functionalization.

Benzoate dioxygenase fromRalstonia eutrophaB9 – unusual regiochemistry of dihydroxylation permits rapid access to novel chirons

Oxidation of benzoic acid by a microorganism expressing benzoate dioxygenase leads to the formation of an unusualipso,orthoarenecis-diol in sufficient quantities to be useful for synthesis.

New oligomers of conduritol-F and muco-inositol. Synthesis and biological evaluation as glycosidase inhibitors

Several oligomers possessing the configuration of conduritol-F and muco-inositol have been prepared and tested against six glycosidase enzymes. Electrochemical dehalogenation and reductive deprotection of cinnamyl ethers are featured in the reported syntheses. The synthesis, properties, and biological activities are investigated.

Total synthesis and biological evaluation of Amaryllidaceae alkaloids: narciclasine, ent-7-deoxypancratistatin, regioisomer of 7-deoxypancratistatin, 10b-epi-deoxypancratistatin, and truncated derivatives

Biocatalytic approaches have yielded efficient total syntheses of the major Amaryllidaceae alkaloids, all based on the key enzymatic dioxygenation of suitable aromatic precursors. This paper discusses the logic of general synthetic design for lycoricidine, narciclasine, pancratistatin, and 7-deoxypancratistatin. Experimental details are provided for the recently accomplished syntheses of narciclasine, ent-7-deoxypancratistatin, and 10b-epi-deoxypancratistatin via a new and selective opening of a cyclic sulfate over aziridines followed by aza-Payne rearrangement. The structural core of 7-deoxypancratistatin has also been degraded to a series of intermediates in which the amino inositol unit is cleaved and deoxygenated in a homologous fashion. These truncated derivatives and the compounds from the synthesis of the unnatural derivatives have been tested against six important human cancer cell lines in an effort to further develop the understanding of the mode of action for the most active congener in this group, pancratistatin. The results of the biological activity testing as well as experimental, spectral, and analytical data are provided in this manuscript for all relevant compounds.

A chemoenzymatic total synthesis of ent-bengamide E

The cis-1,2-dihydrocatechol 3, which can be obtained in enantiomerically pure form by microbial dihydroxylation of bromobenzene, has been converted into the enantiomer, ent-1, of the cyclolysine-based marine natural product bengamide E (1).