Pd-Catalyzed Decarboxylative Cycloaddition of Vinylethylene Carbonates with Isothiocyanates

Abstract

An efficient route for formal [3 + 2] cycloaddition of vinylethylene carbonates with isothiocyanates was developed for the synthesis of 1,3-oxazolidine-2-thione derivatives. The zwitterionic π-allyl palladium intermediates formed in situ by decarboxylation of VECs acted as the three-membered synthons. In this transformation, the C−N bond formation was selectively realized over the C−S bond formation.

Copper-catalyzed S-arylation of Furanose-Fused Oxazolidine-2-thiones

“…The silylation process directly produced a selective protection of the hydroxyl groups of the three pentose OZTs 1, 2, and 3. The corresponding silyl-protected OZTs (6)(7)(8) were obtained in very good yields of 96%, 98%, and 95%, respectively. D-arabinofuranose-, D-xylofuranose-, and D-ribofuranose-derived oxazolidine-2thiones 1-3 can easily be obtained from the corresponding carbohydrates using potassium thiocyanate under acidic conditions [2,36,47].…”

“…The silylation process directly produced a selective protection of the hydroxyl groups of the three pentose OZTs 1, 2, and 3. The corresponding silyl-protected OZTs (6)(7)(8) were obtained in very good yields of 96%, 98%, and 95%, respectively.…”

“…On the other hand, sulfur-containing compounds play an important role in organic synthesis and have been found in various natural products; they also appear in pharmaceuticals, agrochemicals, and functional materials [ 8 , 9 ]. Notably in asymmetric synthesis, a small heterocycle, 1,3-oxazolidine-2-thione (OZT), is a key molecule when chiral.…”

Advances in Palladium‐Catalyzed Decarboxylative Cycloadditions of Cyclic Carbonates, Carbamates and Lactones

“…Significantly, the developed methodology was successfully applied to the synthesis of key intermediate of MK‐0731 (Scheme 21). [10c] Similarly, the DCs of VECs and Isothiocyanates were disclosed by Xu and coworkers [13a] . Using the complex of Pd 2 (dba) 3 ⋅CHCl 3 and racemic BINAP as catalyst in toluene at 60 °C, the DCs proceeded smoothly, delivering 1,3‐oxazolidine‐2‐thione derivatives in good yields (up to 94 % yield).…”

Chiral Bidentate Phosphoramidite-Pd Catalyzed Asymmetric Decarboxylative Dipolar Cycloaddition for Multistereogenic Tetrahydrofurans with Cyclic N-Sulfonyl Ketimine Moieties

“…Notably, vinylethylene carbonates (VECs) as a type of zwitterionic allylpalladium precursor are more stable and readily accessible than the traditional butadiene oxide and isoprene oxide . The zwitterionic allylpalladium intermediates from VECs can undergo the asymmertirc cycloaddition process with diverse substrates including aldehydes, imines, isothiocyanates, and methyleneindolinones alkenes with impressive outcomes. Just recently, Kim and co-workers reported Pd-catalyzed asymmetric [3 + 2] and [5 + 2] cycloadditions of sulfamate-derived cyclic imines and VECs in the presence of a phosphoramidite ligand or a diphosphine ligand, respectively (Scheme a) .…”