Synthesis of Cyclopropane‐Containing Phosphorus Compounds by Radical Coupling of Butenylindium with Iodo Phosphorus Compounds

Abstract

The radical coupling of α-or β-iodo phosphorus compounds such as iodo phosphonate, iodo phosphane oxide, and iodo phosphonothioate with butenylindium species, prepared by transmetalation between a (cyclopropylmethyl)stannane and InBr 3 , afforded the corresponding cyclopropylmethylated products. The radical reaction was initiated by the radical species generated from butenylindium assisted by a small amount of oxygen. Butenylindium works not only as a cyclopropylmethylating reagent, but also as a radical initiator. For

Indium(III) Halide-Catalyzed UV-Irradiated Radical Coupling of Iodomethylphosphorus Compounds with Various Organostannanes

“…Neither reaction, however, proceeded effectively. In the case of Grignard reagent 9 , MgCl 2 given after transmetalation as a byproduct negatively affected the coupling due to its high Lewis acidity, which agreed with the results in our previous work . In fact, the reaction was disturbed by the addition of MgCl 2 to our Sn/In transmetalation system (see the Supporting Information).…”

“…In the case of Grignard reagent 9, MgCl 2 given after transmetalation as a byproduct negatively affected the coupling due to its high Lewis acidity, which agreed with the results in our previous work. 7 In fact, the reaction was disturbed by the addition of MgCl 2 to our Sn/In transmetalation system (see the Supporting Information). In the case of a reductive method using crotyl bromide 10, the indium species are considered to be a mixture of mono-and dicrotylindium.…”

“…6 We have previously developed an equimolar radical coupling between iodomethylphosphorus compounds and butenylindium species generated from cyclopropylmethylstannanes and InBr 3 . 7 Herein, we expand the results to the indium(III) halide-catalyzed reaction of allylic stannanes with iodomethylphosphorus, in which allylic indiums were found to be superior radical partners under UV irradiation by comparison with the corresponding allylstannanes. The catalytic protocol was also applicable to the introduction of alkynyl or propargyl moieties into phosphonyl compounds using either an alkynylstannane or an allenylstannane, respectively.…”

In Situ Dearomatisation/Alkylation of Arylphosphane Derivatives

“…tert-Butylmethylphenylphosphane-borane (1), [30] benzyl-tert-butylphenylphosphane-borane (2), [31] dimethylphenylphosphane-borane (3), [27] diphenyl(iodomethyl)phosphane oxide (6), [32] diethyl 2bromoethylphosphonate (8), [33] tert-butylmethylphenylphosphane oxide (26) [34] and dimethylphenylphosphane oxide (27) [26] were prepared as reported in the literature.…”

Fragmentation of Carbohydrate Anomeric Alkoxyl Radicals: Synthesis of Chiral Polyhydroxylated β‐Iodo‐ and Alkenylorganophosphorus(V) Compounds

“…Such compounds have been prepared by halogen or OTs/I exchange under Finkelstein conditions5 or by metallo‐phosphorylation of zirconocene‐alkene complexes with chlorophosphate using iodine as electrophile 6. Studies on the chemical reactivity of these compounds have largely been limited to diethyl 2‐iodoethylphosphonate 5a,5c,7. In the context of carbohydrate‐containing phosphorus compounds, a point of interest is the preparation of analogues in which the anomeric carbon has been replaced by an atom of phosphorus,8 the so‐called cyclic phostones8o or, more correctly, 1‐phospha sugars 8p.…”