ChemInform Abstract: PHOSPHORYLATION OF ALDOKETENIMINES

Abstract

Aus dem Chloracetylen‐phosphonat (I) und tert.‐Butylamin (II) bildet sich das N‐tert.‐Butyl‐ketenimin‐dimethylphosphonat (III).

Synthesis of Tetrazole-Containing C-Phosphonoacetamidines

“…2-(N-tert-Butyl-or N-adamantyl)iminoethenylphosphonates 1a,b have been accessible due to reacting chloroacetylenephosphonate with the primary amines containing bulky substituents such as tert-butyl or adamantyl moiety. 30 This reaction is analogous to the previously described interaction of secondary and tertiary amines with chloroacetylenephosphonate leading to the formation of ynaminephosphonates, 31 but in this case the presence of two hydrogen atoms on the nitrogen in the amine source enables subsequent prototropic isomerization to form aldoketenimines (Scheme 1).…”

“…They have combined reactivity modes as both electrophiles and nucleophiles. 30,33 Like ketenimines, 34 reactions of phosphorylated aldoketenimines with nucleophiles usually occur regioselectively via nucleophilic attack at the C-2 digonal carbon atom adjacent to the nitrogen atom of the imino group. For example, phosphorylated ketenimines react with alcohols and amines to yield the corresponding β-iminoalkanephosphonate derivatives.…”

“…For example, phosphorylated ketenimines react with alcohols and amines to yield the corresponding β-iminoalkanephosphonate derivatives. 30,33 Addition of CH acids to phosphorylated aldoketenimines also proceed via previous formation of imino adduct followed by prototropic isomerization to give β-aminoalkenephosphonate. 29 The literature data concerning the reactions of N-nucleophiles with phosphonoketenimines are scarce.…”

Dialkyl 1-Alkynylphosphonates: a Range of Promising Reagents

“…[115] The use of tert-butylamine in the reaction with 6 also induces the replacement of halogen, but the reaction is accompanied by isomerisation, giving almost quantitative yields of stable ketenimines. [118,119] The presence of two hydrogen atoms at the nitrogen in the amines permits subsequent prototropic isomerisation with the formation of ketenimines. By way of contrast, reactions with primary phosphines lead to halogen-replaced products with the retention of C≡C bond and P-H bonds.…”