Dong, Ziyang published the artcileDual roles of bisphosphines and epoxides: Rh-catalyzed highly chemoselective and diastereoselective (3 + 2) transannulations of 1,2,3-thiadiazoles with cyanoepoxides, Recommanded Product: Ethyl 3-(4-iodophenyl)-3-oxopropanoate, the main research area is cyanoepoxide thiadiaazole rhodium catalyst chemoselective diastereoselective regioselective cycloaddition; oxiranyl isothiazole preparation.
A highly diastereoselective and chemoselective (3 + 2) transannulation of 1,2,3-thiadiazoles with cyanoepoxides was discovered. The use of sterically larger DPEPhos allows the preparation of cis-epoxyl isothiazoles from cis-cyanoepoxides in up to 95% yields and 100 : 0 dr, while the use of sterically smaller DPPF allows the synthesis of trans-products from cis- or trans-cyanoepoxides in up to 95% yields and 100 : 0 dr. Bisphosphines and epoxides play dual roles. Bisphosphines served not only as ligands, but also as catalysts to catalyze the isomerization of cis-epoxides to trans-isomers. The diastereoselectivity was controlled by the kinetic competition between the direct transannulation of cis-cyanoepoxides and the bisphosphine-catalyzed isomerization of cis-products. The epoxy group’s large steric hindrance guarantees excellent chemoselectivity toward the (3 + 2) annulation, and its electron-withdrawing ability significantly improves the reactivity of the adjacent cyano group. To address the controversy over the organorhodium intermediates, this study suggested the resonation between Lee’s umpolung 1,3-dipoles, Bao’s cyclometalated Rh(III) complexes, and thioacyl-coordinated Rh(I) carbenes. Stereospecific access to isothiazole-fused γ-lactone was also developed.
Organic Chemistry Frontiers published new progress about [3+2] Cycloaddition reaction catalysts (chemo and stereoselective). 63131-30-6 belongs to class iodides-buliding-blocks, name is Ethyl 3-(4-iodophenyl)-3-oxopropanoate, and the molecular formula is C11H11IO3, Recommanded Product: Ethyl 3-(4-iodophenyl)-3-oxopropanoate.
Referemce:
Iodide – Wikipedia,
Iodide – an overview | ScienceDirect Topics – ScienceDirect.com