Evidently so: New mechanistic findings indicate that addition of dialkyl trimethylsilyl phosphites to α,β‐unsaturated imines has been incorrectly reported as an exclusive 1,2‐addition. When α,β‐unsaturated imines are used as substrates, 1‐alkylamino 3‐phosphonyl phosphonates are formed in high yields in the presence of a suitable proton source through a sequential 1,4‐ and 1,2‐addition.

Erwiesenermaßen: Neueste Ergebnisse widerlegen die bisherige Annahme, dass die Addition von Dialkyl(trimethylsilyl)phosphiten an α,β‐ungesättigte Imine ausschließlich die 1,2‐Addukte ergibt. Mit diesen Iminen als Substraten entstehen in Gegenwart einer Protonenquelle durch sequenzielle 1,4‐ und 1,2‐Addition 1‐Alkylamino‐3‐phosphonylphosphonate in hohen Ausbeuten.

Organo-phosphorus compounds S 0080Tandem Addition of Trialkyl Phosphites to α,β-Unsaturated Imines: A Comparison with Silylated Phosphites. -Treatment of α,β-unsaturated imines with 2 equiv. of trialkyl phosphites and HCOOH results in formation of biologically interesting bisphosphonates of type (III). However, starting from sterically hindered imines such asIe) only 1,4-addition is observed. -(VAN MEENEN, E.; MOONEN, K.; VERWEE, A.; STEVENS*, C. V.; J. Org. Chem. 71 (2006) 20, 7903-7906; Dep. Org. Chem., Fac. Biosci. Eng., Univ. Gent, B-9000 Gent, Belg.; Eng.) -Jannicke 06-163

Organo-phosphorus compounds S 0080One-Pot Tandem 1,4-1,2-Addition of Phosphites to α,β-Unsaturated Imines for the Synthesis of Glutamic Acid Analogues. -Dialkyl trimethylsilyl phosphite (II) reacts with α,β-unsaturated imines (I) and (IV) in a sufficiently acidic medium to give diphosphonates (III) and (V), resp., by tandem 1,4-1,2-addition pathway. The reaction mechanism is discussed in detail. -(MOONEN, K.; VAN MEENEN, E.; VERWEE, A.; STEVENS*, C. V.; Angew. Chem., Int. Ed. 44 (2005) 45, 7407-7411; Dep. Org. Chem., Fac. Biosci. Eng., Univ. Gent, B-9000 Gent, Belg.; Eng.) -Mischke 12-175