Reactions of (1-Diazo-2-oxoalkyl)silanes with 3 H -1,2,3,4-Triazaphospholes: a Route to Short-Lived 4-Imino-1,2,4(λ 5 )-diazaphospholes

Cycloaddition reactions of heterophospholes

“…Recently [3 + 2] cycloadditions of (1-diazo-2-oxoalkyl)silanes have been investigated with 2H-1,2,3-diazaphospholes [81], 3H-1,2,3,4-triazaphospholes [82], and 1,2-thiaphospholes [53]. The silanes 61 are in equilibrium with minor amounts of diazocumulenes 62 which are much more reactive 1,3-dipoles than the former [83].…”

“…Their reaction with 2H-1,2,3-diazaphospholes 63 affords the [3 + 2] cycloadducts 64. The latter on thermolysis change into the tricyclic heterocycles 65 through loss of nitrogen 5 -diazaphosphole which, depending on the nature of the imino substituent, undergoes dimerization across P N (imino substituent Ph) to yield 67 or a 1,3(C → P) OR migration (iminosubstituent COOR) to generate 69 [82].…”

Syntheses and spectroscopic investigation of some cyclophosphazanes: Analysis of pseudo‐triplet splitting

“…The wide range applications of cyclophosphazanes in nucleophilic substitution reactions on P Cl bonds [6,7], coordination chemistry [8], and ring-opening polymerization reactions [9] causes a significant attraction to this area of chemistry. There are many articles reporting the synthesis and structure of phosphorus(III) [10][11][12][13][14][15] and phosphorus(V) cyclophosphazane compounds [16][17][18][19][20][21].…”

Cycloaddition Behavior of 1,2‐Thiaphospholes: Reactions with Diazocumulenes and with Cyclopentadiene

“…[6] Diazo dipoles [8] were also found to react with a 1,3,4-thiazaphosphole [9] and with 1,2,3,4-3H-triazaphospholes. [10] Märkl and Hölzl in 1988Ϫ89 reported the first preparations of 1,2-thiaphospholes in very low yields. [11,12] The first practical synthesis was published by Saito and co-workers in 1993.…”

“…Based on the smooth cycloaddition reaction of α-diazo-α-silyl ketones (via their diazocumulene isomers, see Scheme 1) with 2-acyl-1,2,3-diazaphospholes [16] and 1,2,3,4-3H-triazaphospholes, [10] we became attracted to 1,2-thiaphospholes as potential dipolarophiles. Furthermore, since no reactions with cyclopentadienes have been reported in the literature, we wondered whether the PϭC bond of 1,2-thiaphospholes could also serve as a dienophilic component in DielsϪAlder reactions.…”