Electrochemically Supported Deoxygenation of Epoxides into Alkenes in Aqueous Solution

Abstract

An efficient synthesis of alkenes from epoxides in a mixture of saturated aqueous NH(4)Br and tetrahydrofuran (8:1) has been developed in an undivided cell fitted with a pair of zinc electrodes, and it is proposed that the reaction is mediated by Zn(0) with a hierarchically organized nanostructure.

Synthetic Organic Electrochemical Methods Since 2000: On the Verge of a Renaissance

“…871 The use of zinc electrodes is critical—this reaction is putatively mediated by Zn(0) generated in situ through the sequential oxidation and reduction of the electrode material. Such zinc deposits were found to adopt a hierarchically organized nanostructure.…”

Cobalt Catalysis Enables Regioselective Ring-opening of Epoxides with Aryl Halides

“…Acetophenone (8a a side-product originating from epoxide 5a) formed in 5% yield presumably via β-hydride elimination, while styrene (10a) forms in 30% yield from intermediate alcohol 9. 39 Finally, the reductive elimination in the nickel cycle may account for the observed small amount of biphenyl 11. [40][41][42] Substrate scope -With the optimized conditions in hand, we explored the scope and limitations of the developed method.…”

Oxidative β-Halogenation of Alcohols: A Concise and Diastereoselective Approach to Halohydrins

“…The reaction of 1-(naphthalen-2-yl)ethan-1-ol 3a (86.1 mg, 0.5 mmol) and 98% H 2 SO 4 (200 mg, 2 mmol) in DMSO (1 mL) at 60 o C for 24 h, affords 40.9 mg (53%) of 2-vinylnaphthalene 11 12 as a white solid. 1 H NMR (400 MHz, CDCl 3 ) δ 7.82 -7.76 (m, 3H), 7.74 (d, J = 1.6 Hz, 1H), 7.63 (dd, J = 8.6, 1.8 Hz, 1H), 7.49 -7.40 (m, 2H), 6.88 (dd, J = 17.6, 10.9 Hz, 1H), 5.87 (dd, J = 17.6, 0.8 Hz, 1H), 5.33 (dd, J = 10.9, 0.8 Hz, 1H).…”

“…The reaction of trans-1,2-dibromo-1,2,3,4-tetrahydronaphthalene 12 (145.0 mg, 0.5 mmol) synthesized according ref. 11 and 98% H 2 SO 4 (200 mg, 2 mmol) in DMSO (1 mL) at 60 o C for 24 h. After concentrating in vacuo, the yield and d.r. value was determined by crude 1 H NMR.…”