Flash vacuum pyrolysis of stabilised phosphorus ylides. Part 8. Preparation of symmetrical and unsymmetrical 1,3-diynes from alkynoyl ylides and oxalyl diylides

Solution and Solid State Structure of Highly Delocalised 5- Triphenylphosphoranylidenecyclopen Tene-3,4-Diones

“…The resulting coupling constants are not only consistent between 4 and 5, but also in agreement with the values previously reported for R.ALANAITKENf/a/. EtO' p,Y,P'-trioxo ylides, 2 oxalyl diylides, 3 and P,y-dioxo ylides. 4 The only possible ambiguity is in the region of 5 C 179-186 where there are three doublets and a singlet corresponding to C-l, C-3, C-4 and ArCO.…”

Kinetics and mechanism of gas‐phase pyrolysis of ylides. Part 3.1 Thermal reactivity of α‐carbonyl‐ and thiocarbonyl‐stabilized methylenetriphenylphosphoranes

“…m.p. 183–185 °C;36 1 H NMR(CDCl 3 ): δ 1.23(s, 9H), 3.82 (brs, 1H), 7.50–7.96 (m, 15H) 37 . 31 P NMR(CDCl 3 ): δ 17.27 37.…”

“…Diphenylbutadiyne (C 6 H 5 CCCCC 6 H 5 ) (from ylide 1c ) as colorless crystals, 1 H NMR (CDCl 3 ): δ 7.20–7.30 (m, 6H), 7.40–7.50 (m, 4H) 36 . 13 C NMR (CDCl 3 ): δ 73.90, 81.50, 121.80, 128.40 (2C), 129.20, 132.5 (2C) 36…”

The Usefulness of Phosphorus Compounds in Alkyne Synthesis

“…With the same technique, a number of functionalized alkynes were prepared in moderate yields including, benzofurans via the 2-methoxyphenylalkynes and benzothiophenes via 2-methylthiophenylalkynes, 85,86 diacylalkynes, 87,88 terminal 1,3-diynes, 89 and unsymmetrical 1,3-diynes, 90 1,3-enynes, 91 pyrroloisoindolediones, 92 styrylalkynes, substituted naphthalenes, 93,94 and protected acetylenic amino acids. 95 The limit of the usefulness of the FVP technique was reached with the pyrolysis of the tetraoxo ylides and hexaoxo bis(ylides).…”