Cyanomethylenetriphenylphosphorane

Synthesis of Functionalised Phosphonates by Three-Component Reaction between Phosphites, Dialkyl Acetylenedicarboxylates and Pyrrole, Indole or Benzotriazole

“…On the basis of the well-established chemistry of trivalent phosphorus nucleophiles [1][2][3][4][5][6][7] it is reasonable to assume that compounds 4 and 5 are resulted from the initial addition of phosphite to acetylenic ester and subsequent protonation of the 1 : 1 adduct by pyrrole (Scheme 3). Then, the positively charged ion 6 is attacked by the anion of pyrrole 7.…”

“…The successful attack by nucleophilic trivalent phosphorus on a carbon atom is facilitated when the later is conjugated with a carbonyl group or when it is part of an unsaturated bond otherwise activated. [1][2][3][4][5][6][7][8] There have been many studies on reactions between trivalent phosphorus nucleophiles and unsaturated carbonyl compounds in the presence of a proton source such as an alcohol. 1 The reaction of phosphites and dimethyl acetylenedicarboxylate (DMAD) in the presence of naphthols reported to produce phosphonate derivatives.…”

Diastereoselective Synthesis of Functionalised Phosphonates by Three-Component reaction between Phosphites, Acetylene Diesters and Formanilides

“…The attack by trivalent phosphorus nucleophiles on carboncarbon multiple bonds is facilitated when the latter are activated by a strong electron-withdrawing group such as a carbonyl. [1][2][3][4][5][6][7][8] The conjugate addition of phosphites to acetylenic esters produces a zwitterionic intermediate which may be trapped by various carbon or hydrogen electrophiles. For example, the reaction between trialkyl phosphites and dialkyl acetylenedicarboxylates (DAAD) in the presence of organic N-H, OH and C-H acidic compounds has been reported to produce phosphite ylides which may be isolated as stable compounds 9,10 or hydrolysed to phosphonate derivatives.…”

Stereoselective One-Pot Synthesis of Functionalised Phosphonates by Three-Component Reaction between Trimethylphosphite, Dialkyl Acetylenedicarboxylates and Aldehyde Semicarbazones

“…The successful attack by nucleophilic trivalent phosphorus on a carbon atom is facilitated when the later is conjugated with a carbonyl group or when it is part of an unsaturated bond otherwise activated. [1][2][3][4][5][6][7][8] There have been many studies on reactions between trivalent phosphorus nucleophiles and unsaturated carbonyl compounds in the presence of a proton source such as an alcohol. 1 The reaction of phosphites and dimethyl acetylenedicarboxylate (DMAD) in the presence of naphthols reported to produce phosphonate derivatives.…”

“…On the basis of the well-established chemistry of trivalent phosphorus nucleophiles [1][2][3][4][5][6][7] it is reasonable to assume that compounds 3 result from the initial addition of trimethylphosphite to acetylenic ester 2 and subsequent protonation of the 1 : 1 adduct by semicarbazone 1 (Scheme 3). Then, the positively charged ion 4 is attacked by the anion of semicarbazone to form ylide 5 that is hydrolysed to phosphonate 3.…”