Enhancing the reactivity of 1,2-diphospholes in cycloaddition reactions

• Almaz Zagidullin,
• Vasili Miluykov,
• Elena Oshchepkova,
• Artem Tufatullin,
• Olga Kataeva and
• Oleg Sinyashin

Beilstein J. Org. Chem. 2015, 11, 169–173, doi:10.3762/bjoc.11.17

• : cycloaddition; phospholes; phosphorus heterocycles; polycyclic phosphines; retro-Diels–Alder reaction; Introduction Phospholes are weakly aromatic heterocycles and demonstrate rather different properties from those of their S, N and O counterparts [1][2]. Due to low their aromaticity, phospholes are of

Relay cross metathesis reactions of vinylphosphonates

• Raj K. Malla,
• Jeremy N. Ridenour and
• Christopher D. Spilling

Beilstein J. Org. Chem. 2014, 10, 1933–1941, doi:10.3762/bjoc.10.201

• of vinylphosphonate 21a with styrenes. The dimeric product 27 was not observed during the cross metathesis of the vinylphosphonate 21a with methyl acrylate. Diallyl vinylphosphonates (28) are reported to undergo ring closing metathesis to give either 7-membered (29) or 5-membered (30) phosphorus

• heterocycles (Scheme 8) [23][24]. The mode of cyclization depends upon the geometry and substitution of the vinylphosphonate. It was proposed that (E) diallyl vinylphosphonates would prefer to form the 5-membered ring oxaphosphole 30 and therefore, like the corresponding mono-allyl phosphonates, should engage