Metal Salt-Promoted Alcoholysis of 1,2-Epoxides

One-Pot Catalytic Synthesis of 2-(1,2-Dihydroxypropyl)phenol Derivatives from 2-Allylphenols in Aqueous Media

“…A plausible mechanism, depicted in Scheme 1, would involve three successive reactions which could be Pd(II)mediated: isomerisation of the substrate, 6 epoxidation of the double bond, 8,9 and hydrolysis or alcoholysis of the oxirane. 10 In agreement with the above proposals, subjecting 2a to the conditions used in Table 1 (H 2 O-MeOH) led to 3a and 4a in 88% yield (Equation 2). Furthermore, the fixation of the methoxy group exclusively at the benzylic position by methanolysis of aryl epoxides under acidic conditions has already been reported.…”

Conversion of Epoxides to Halohydrins with Elemental Halogen Catalyzed by Phenylhydrazine

“…A contra-Markovnikov-type, 13,14 regioselectivity is generally observed in these reactions. In many cases, this type of regioselectivity appears to be opposite of that observed in the ring opening of the same epoxides with aqueous hydrohalogenic acids, under classic conditions 15 (entries 1 and 10). Halogenative cleavage of epoxides occurs according to the following four-step mechanism: The first step (Equation 1) involves the formation of a 1:2 or 1:1 molecular complex between phenylhydrazine and elemental halogen, in which halogen ion (X 3 -) exists as a contact ion pair:…”

SO3H-Carbon derived from glycerol: An efficient and recyclable catalyst for smooth and regioselective azidolysis of oxiranes in water

“…Ring opening reactions of epoxide with nucleophiles are considered as an interesting approach in organic synthesis of many functionalized oxygenated compounds. The reaction with nucleophiles such as oxygen compounds (Water, alcohols and phenols) [6][7][8][9][10], nitrogen compounds (Amine, amine derivatives, azide, nitrate, and isocyanate) [11][12][13], halides [14], and various carbon nucleophiles [15] have been performed in both organic and aqueous solvents. Among the numerous products from nucleophilic reactions of epoxide, vicinal azidohydrins [16] exhibit key role in organic synthesis as potential precursors for 1,2-aminoalcohols which are well known as β-blockers and a common structural component in vast group of natural products [11,[17][18][19][20], and often used in carbohydrate chemistry or in the chemistry of carbocyclic nucleosides [11,16] can be obtained through the nucleophilic ring opening of epoxides with azide nucleophile [21][22][23][24].…”