Copper‐Catalyzed β‐Iodovinylation of Carbamates: Expedient Access to Highly Functionalized Vinyl‐Carbamates

Abstract

A general and efficient method for the synthesis of β‐iodovinyl carbamates via copper‐catalyzed β‐iodovinylation of acyclic carbamates is described. This method uses readily available (E)‐1,2‐vinyl diiodides and regioselectively affords the corresponding β‐iodovinyl carbamates in good yields with complete stereocontrol of the alkene. Further functionalization of these versatile products leads to a wide diversity of β‐functionalized vinyl‐carbamates in good to excellent yields.

Synthesis of oxazolidinones from N-aryl-carbamate and epichlorohydrin under mild conditions

“…The derivatives 3i,7-9 14 and toloxatone 35 were synthetized as previously reported. 1 NMR spectroscopic data of the known compounds 3b, 41 3e, 42 3f, 43 3g, 44 3h, 45 5a, 46 5b, 37 5d, 46 5f, 35 5h, 47 6h, 44 9, 14 10, 37 and DuP 721 37 are consistent with literature.…”

“…Consistent with literature. 44 Ethyl 3-fluoro-4-morpholinophenylcarbamate (3h). White solid; mp: 121-123°C; yield 25%; 1 H NMR (300 MHz, CDCl3) δ: 1.31 (t, J 7.2 Hz, 3H, CH3), 3.04 (t, J 4.5 Hz, 4H, CH2), 3.87 (t, J 4.5 Hz, 4H, CH2), 4.23 (q, J 7.2 Hz, 2H, CH2), 6.57 (s, 1H, NH), 6.85-6.91 (m, 1H, arom.…”

(E)-Di-iodination of Alkynes Using Dried Dowex H+/NaI Approach

“…The purity of the products was determined from 1 H spectrum and was ≥95% unless stated otherwise. All starting materials (1−12) and the Dowex H + ion-exchange resin used in the study were commercially available; however, isopropyl hex-5-ynoate (7) was prepared using the method we reported recently. 35 Example of the Preparation of Dried Dowex H + Ion-Exchange Resin.…”

“…Common methods for di-iodination reported in the literature consist of the use of hazardous and/or toxic compounds, such as oxidants, e.g., H 2 O 2 , 3 iodine sources, e.g., trimethylsulfonium iodate 4 and iodine monochloride, 5 reagents like tetrafluoroboric acid 6 and solvents, e.g., dichloromethane, 5 dioxane, 6 or tetrahydrofuran. 3 Some procedures also use heavy-metal catalysts, like copper 7 or cobalt. 8…”

“…Common methods for di-iodination reported in the literature consist of the use of hazardous and/or toxic compounds, such as oxidants, e.g., H 2 O 2 , 3 iodine sources, e.g., trimethylsulfonium iodate 4 and iodine monochloride, 5 reagents like tetrafluoroboric acid 6 and solvents, e.g., dichloromethane, 5 dioxane, 6 or tetrahydrofuran. 3 Some procedures also use heavy-metal catalysts, like copper 7 or cobalt. 8 Iodinated compounds are indispensable building blocks in organic chemistry; they are extensively used in the creation of new covalent bonds, e.g., C−C, 9,10 C−N, 11−13 C−O, 14,15 C− B, 16,17 C−S, 18,19 and C−metal 20,21 bonds.…”