602331-03-3Relevant academic research and scientific papers
Propyne iminium salts and phosphorus(III) nucleophiles: Synthesis of (3-morpholinoallenyl)phosphanes and -phosphane oxides or 1-(morpholinopropargyl)phosphanes and -phosphonates
Reisser, Martin,Maier, Alexandra,Maas, Gerhard
, p. 2071 - 2079 (2003)
Treatment of 4-(1,3-diphenyl-l-propynylidene)morpholinium triflate (1a) with the neutral phosphorus nucleophiles Me3Si-PPh2, Me3Si-P(Ph)C5H11, and Me3SiO-PPh2 affords (3-morpholinoallenyl)phosphanes 4 and 5 and (3-morpholinoallenyl)phosphane oxide 11, respectively. In contrast to these conjugate addition reactions at the ambident propyne iminium moiety of 1a, nucleophilic attack by Me3Si-PEt2 and Me3SiO-P(OEt)2 takes place at the iminium function and gives (1-morpholinopropargyl)phosphane 6 and (1-morpholinopropargyl)phosphonate 12, respectively. Propyne iminium salt 1b reacts with Me3Si-PPh2 to form (3-morpholino-1,3-butadienyl)phosphane oxide 8. The bis(donor)-substituted allene 4 is transformed by oxidation of the phosphorus substituent into the push-pull substituted allenylphosphane oxide 11. Treatment of allene 4 with elemental sulfur results in the formation of betaine 16, which undergoes [3+2] cycloaddition reactions with acetylenic esters to afford 5-benzylidene-4,5-dihydrothiophenes 17 and 18. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
