N → C₂ → C₃ migration of the dichlorophosphino group in the synthesis of phosphorylated NH‐pyrroles

N → C3 migration of dichlorophosphino group in the phosphorylation of N‐unsubstituted indole with phosphorus trichloride

“…A similar N → C 3 sigmatropic rearrangement of phosphorylated indoles occurs in the hydrolysis and alcoholysis of N-indolylamidophosphite with respective equimolar amounts of water or alcohol [6]. As previously found by us [7], the phosphorylation of unsubstituted pyrrole with phosphorus trichloride in polar solvents leads to a successive N → C 2 → C 3 migration of the dichlorophosphino group in the pyrrole nucleus. Here we address the same N → C rearrangement in unsubstituted indole; it shows much synthetic promise affording 3-indolyldichlorophosphine, a key compound in the preparation of various P-and N-functionalized phosphorylated indoles.…”

Phosphine-substituted sterically encumbered pyrrolyl ligands – synthesis and reactivity studies

“…s, 1H, NH), 7.63-7.58 (m, 4H, ortho-CH-Ph), 6.82-6.77 (m, 4H, meta-CH-Ph), 6.74-6.71 (m, 2H, para-CH-Ph), 6.59 (dd, 4 J HH = 3.0 Hz, 3 J PH = 7.1 Hz, 1H, CH-Pyr, 1.18 (s, 9H, C-5-C(CH 3 ) 3 , 0.91 (s, 9H, C-2-C(CH 3 ) 3 ,) ppm. 13 (53,46), 603.1 (40,38), 597 (36,34), 596.1 (17,17), 604.1 (12,15), 605.1 (1,1). IR (ATR; cm −1 ): 3481 (m, NH), 2066 (m, CO), 1927 (sh, CO), 1907 (vs.br, CO).…”

“…Only recently a detailed study on the reactivity of unsubstituted pyrrole with PCl 3 has been reported, in which a successive N → C2 → C3 migration of the PCl 2 -group was observed. 34 Whereas tetramethylpyrrole reacts with PCl 3 exclusively at the N-atom, 35 phosphorylation of 2,5-dimethylpyrrole occurs exclusively at the C3-position. 34 In our previous contributions we reported on the synthesis of several sterically encumbered pyrrolyls and the subsequent synthesis of several azatrozircenes [(η 7 -C 7 H 7 )Zr(η 5 -Pyr′)] 36,37 and more recently of diazaferrocenes.…”

“…34 Whereas tetramethylpyrrole reacts with PCl 3 exclusively at the N-atom, 35 phosphorylation of 2,5-dimethylpyrrole occurs exclusively at the C3-position. 34 In our previous contributions we reported on the synthesis of several sterically encumbered pyrrolyls and the subsequent synthesis of several azatrozircenes [(η 7 -C 7 H 7 )Zr(η 5 -Pyr′)] 36,37 and more recently of diazaferrocenes. 38 Herein, we detail the synthesis of phosphinesubstituted pyrroles (Fig.…”