A simple and practical synthesis of sulfonyl fluorides from sulfonamides is reported. The method capitalizes on the formation of the sulfonyl chloride by virtue of the reaction of Pyry-BF 4 and MgCl 2 , and subsequent in situ conversion to the The synthesis of complex organic molecules bearing sulfonyl fluorides in their structure has gained tremendous momentum due to their successful activity in the field of chemical biology. [1,2] Due to its unique chemical properties, several sulfonyl fluorides have been utilized as warheads in chemical biology to target amino acid residues and act as activity-based probes (Figure 1). [3] Numerous synthetic approaches to sulfonyl fluorides are available in the literature, starting from a myriad of different starting materials. [4] Early syntheses can be found from the sulfonyl hydrazide, [5] thiosulfonate, [6] sulfonyl chloride, [2,7] sulfonic acids, [8] sulfonate salts [9] among others (Figure 2A). [10] However, most of these traditional methods are restricted in terms of functional group compatibility and synthetic steps are required to obtain the starting materials. In more recent approaches, Willis and Bagley [11] and Ball [12] independently addressed these issues and reported elegant Pd-catalyzed strategies for the syn-[a]

Simple treatment of chiral titanium(IV) enolates with diacyl peroxides produces highly diastereoselective decarboxylative alkylations to efficiently deliver the corresponding adducts, most of which are not accessible through any of the current alkylating procedures. Such an unprecedented alkylation proceeds through a SET process that triggers the decomposition of the peroxide into a carbon-centered radical that finally combines with the resulting Ca radical. The procedure has been applied to the enantioselective synthesis of arundic acid.

Here, we present a new stereoselective alkylation of titanium(IV) enolates of chiral N -acyl oxazolidinones with tert -butyl peresters from Cα-branched aliphatic carboxylic acids, which proceeds through the decarboxylation of the peresters and the subsequent formation of alkyl radicals to produce the alkylated adducts with an excellent diastereoselectivity. Theoretical calculations account for the observed reactivity and the outstanding stereocontrol. Importantly, the resultant compounds can be easily converted into ligands for asymmetric and catalytic transformations.

Herein, the asymmetric synthesis of umuravumbolide ( 1 ) is described. The new approach features highly stereoselective transformations (dr ≥ 95:5) to install both stereocenters and the Z olefin, which involve a new radical alkylation, an Ando olefination, and a Krische allylation on a Z allylic alcohol, not reported before. The application of such successful reactions, together with the limited use of protecting groups and concession steps, makes it possible to complete the synthesis in 10 steps, resulting in a 39% overall yield from chiral N -acyl oxazolidinone 2 .