Ring-opening Reaction of Oxiranes, Oxetanes, and Tetrahydropyran by Mercury(II) Salts and Alkyl Halides

Abstract

The reaction of primary and secondary alkyl halides with mercury(II) acetate in oxiranes, oxetanes, and tetrahydropyran results in ring-opening to give the corresponding alkoxyalkyl acetates. Similar reactions with mercury(II) thiocyanate in oxetanes afford alkoxyalkyl isothiocyanate and thiocyanate, ROCH2C(R′)2CH2NCS and ROCH2C(R′)2CH2SCN, where the isomer ratios (N/S ratios) are 82–96/4–18. It is suggested that the reactions involve the initial formation of a three-, four-, or six-membered O-alkyloxonium ion intermediate and subsequent attack by XHgZ2−.

Structural control of self-healing silica–poly(tetrahydropyran)–poly(ε-caprolactone) hybrids

“…•OEt2 initiation. 32,34 Then, a nucleophilic attack of the oxygen of THP by BF3 initiated the cationic ring opening polymerization and further chain elongation steps. In this way, covalent bonds were formed between GPTMS and PTHP polymer chains, thus constructing the organic copolymer with HOOC-PCL-COOH (Fig.…”

“…Considering its stable sixmembered cyclic structure with low ring-strain, THP is generally considered to be resistant against ring-opening and thus polymerization under mild conditions. 32 As such, polyTHP (PTHP) is a very uncommon component in biomedical hybrids. 33 However, the cationic ringopening process can possibly solve this in the presence of an epoxide ring with higher ring strain and a suitable Lewis acid (e.g., boron trifluoride diethyletherate) as a catalyst.…”

Propylene Oxide

“…2-Dioxolanimines, 2-oxathiolanimines, and 2-oxazolidinimines result from the reaction of propylene oxide with isocyanates, isothiocyanates, and carbodiimides, respectively (111,112).…”

Inorganic-Organic Hybrid Biomaterials for Bone Regeneration

“…For experiments, PTHP-SiO2 and PTHF-SiO2 hybrids are prepared for comparison due to their similar reaction mechanism and molecular structures. (49,67,68). The extra C atom in the THP monomer should allow for greater tailoring of hybrid mechanical characteristics.…”