Acidity of Cyclic Sulfamates: Study of Substituted 1,2,3-Benzoxathiazole 2,2-Dioxides and Theoretical Investigation of the Effect of Conformation on Acidity

Enantioselective Synthesis of Cyclic Sulfamidates via Pd-Catalyzed Hydrogenation

“…The chiral amino alcohols and 2-aminomethyl phenols are important building blocks in organic synthesis and as well as structural units of agricultural and pharmaceuticals agents . With LiAlH 4 as the nucleophilic reagent, 3a and 5 h were converted to β-amino alcohol 7 and 2-[amino(phenyl)methyl]phenol 8 , respectively, without the loss of the optical purity (Scheme ).…”

Racemization in the Use of N-(9-(9-Phenylfluorenyl))Serine-Derived Cyclic Sulfamidates in the Synthesis of δ-Keto α-Amino Carboxylates and Prolines

“…Serine-derived cyclic sulfamidates have been effectively used as “β-alanyl cation” synthons for the synthesis of α-amino acids because the cyclic sulfamidate can simultaneously activate the β-position to nucleophilic attack and protect the amino group. − Several examples of nucleophilic ring opening of cyclic sulfamidates derived from serine have been described with nitrogen, − oxygen, − ,, sulfur, ,, and fluoride 11,13,17-19 nucleophiles. On the other hand, ring-opened products have rarely been synthesized with carbon nucleophiles 16a other than cyanide. ,,,16a An exception to this trend was the ring opening of (4 S )- tert -butyl 2,2-dioxo-3-benzyl-1,2,3-oxathiazolidine-4-carboxylate with diethyl malonate which produced tert -butyl N -benzyl-4-ethoxycarbonyl pyroglutamate as well as a dehydroalanine side product . Attempting to extend this reactivity with carbon nucleophiles, we have studied N -(PhF)serine-derived cyclic sulfamidate 1 and have discovered a β-elimination/Michael addition pathway that furnished racemic γ-substituted amino acid products.…”

Synthesis and evaluation of analogues of estrone-3-O-sulfamate as potent steroid sulfatase inhibitors

“…7,40 Two of which are i) nucleophilic attack on the sulfur atom of the sulfamoyl group by the hydrated form of formylglycine residue (gem-diol) in the STS active site; and ii) specific or non-specific sulfamoylation by an aryl sulfamate of an essential nucleophilic amino acid residue in the STS active site. Andersen et al 23,24 reported that some 1,2,3-benzoxathiazole 2,2-dioxides (e.g. 22 and 23, Figure 2) are reactive toward nucleophiles.…”

“…al. 23,24 for the synthesis of 1,2,3-benzoxathiazole-2,2-dioxides was applied to the synthesis of 'cyclic sulfamates' (21), (22) and (23). The starting 2-amino (21a) and 4-aminoestrone (23a) were easily obtained by hydrogenating 2-nitro-(1a) and 4-nitroestrone (2a) respectively in the presence of palladium-charcoal.…”