Synthesis approach and biological activity evaluation of a series of 1,3,2-oxazaphosphole-2-oxides against inflammation and nociception

Organocatalytic Diastereoselective (4 + 1) Cycloaddition of o-Hydroxyphenyl-Substituted Secondary Phosphine Oxides

The first organocatalytic diastereoselective (4 + 1) cycloaddition of o-hydroxyphenyl-substituted secondary phosphine oxides (SPOs) has been established, which makes use of o-hydroxyphenyl substituted SPOs as suitable four-atom phosphorus-containing 1,4-dinucleophiles and 3-indolylformaldehydes as competent 1,1-dielectrophiles under Bro̷nsted acid catalysis. The reaction mechanism was suggested to involve the formation of 3-indolylmethanol intermediates and vinyliminium intermediates, which played an important role in controlling the reactivity and diastereoselectivity of the (4 + 1) cycloaddition under Bro̷nsted acid catalysis. By this approach, a series of benzo oxaphospholes bearing P- and C-stereocenters were synthesized in moderate to good yields (50%-95% yields) with excellent diastereoselectivities (all >95:5 dr). This reaction not only represents the first organocatalytic diastereoselective (4 + 1) cycloaddition of o-hydroxyphenyl-substituted SPOs but also provides an efficient and diastereoselective method for the construction of phosphorus-containing benzo five-membered heterocyclic skeletons bearing both P-stereocenter and C-stereocenter.

Click chemistry-based synthesis of new benzenesulfonamide derivatives bearing triazole ring as selective carbonic anhydrase II inhibitors

A series of 1,2,3-triazol-1-ylbenzenesulfonamide derivatives was designed, synthesized and their ability to inhibit several carbonic anhydrase isoforms was evaluated. The basis of our design is to hybridize the benzenesulfonamide moiety widely used as a zinc-binding group, a triazole ring as spacer with a tail of different substituted aryl moieties. The synthesis of these compounds was achieved using Cu(I)-mediated click chemistry between the azide containing the benzenesulfonamide pharmacophore and various aryl acetylenes or 1,6-heptadiyne through copper-catalyzed [3+2] cycloaddition reaction. The ability the new derivatives to inhibit four human carbonic anhydrase isoforms hCA I, II, IX, and XII was evaluated. All the compounds exhibited good potency and high selectivity towards isoforms hCA I and II more than isoforms hCA IX and XII, especially for the derivatives 3c and 3j that displayed Ki of 2.8 and 3.8 nM against hCA II and a high hCA II selectivity ratio ranging from 77.6 to 3571.4 over other isoforms. All the compounds were docked in the active site of the downloaded hCA II active site and their binding pattern confirmed their significant activity by interacting of the sulfonamide moiety with zinc ion in the active site, in addition to its hydrogen bond interaction with Thr199 and Thr200. All the above-mentioned findings pointed out towards the promising activity of the synthesized series that can be presented as a new scaffold to be further optimized as selective antiglaucoma drugs.