Preparation of 2-phospholene oxides by the isomerization of 3-phospholene oxides

• Péter Bagi,
• Réka Herbay,
• Nikolett Péczka,
• Zoltán Mucsi,
• István Timári and
• György Keglevich

Beilstein J. Org. Chem. 2020, 16, 818–832, doi:10.3762/bjoc.16.75

• Analytical Chemistry, University of Debrecen, H-4032 Debrecen, Hungary 10.3762/bjoc.16.75 Abstract A series of 1-substituted-3-methyl-2-phospholene oxides was prepared from the corresponding 3-phospholene oxides by double bond rearrangement. The 2-phospholene oxides could be obtained by heating the 3

• -phospholene oxides in methanesulfonic acid, or via the formation of cyclic chlorophosphonium salts. Whereas mixtures of the 2- and 3-phospholene oxides formed, when the isomerization of 3-phospholene oxides was attempted under thermal conditions, or in the presence of a base. The mechanisms of the various

• double bond migration pathways were elucidated by quantum chemical calculations. Keywords: chlorophosphonium salts; isomerization; 2-phospholene oxides; 3-phospholene oxides; quantum chemistry; Introduction P-Heterocyclic derivatives are valuable targets in synthetic organophosphorus chemistry [1][2][3