159052-03-6

Upstream product

• 119100-22-0 triphenylphosphonium-o-methoxybenzylide 
• 102-92-1 Cinnamoyl chloride 
• 64820-07-1 ((2-methoxyphenyl)methyl)triphenylphosphonium bromide 
• 140-10-3 (E)-3-phenylacrylic acid 

Downstream Products

• 239-30-5 benzo[b]naphtho[2,1-d]furan 
• 205-39-0 benzo[b]naphtho[1,2-d]furan 
• 791-28-6 Triphenylphosphine oxide 

Relevant academic research and scientific papers

Flash vacuum pyrolysis of stabilised phosphorus ylides. Part 14. Tandem cyclisation of intermediate aryloxy and arylthio radicals leading to tri- and tetra-cyclic aromatic heterocycles

Seven new stabilised phosphorus ylides 8-14 designed to undergo thermal tandem cyclisation have been prepared. Upon flash vacuum pyrolysis at 850°C, loss of Ph3PO and Me? results in tandem cyclisation to give benzothieno[3,2-b]benzothiophene 16 in the case of 11 while for 8 an abstraction-rearrangement-extrusion sequence leads to 2-phenylbenzofuran 18. For 9 and 10 both types of process occur to give respectively benzothieno[3,2-b]benzofuran 27, prepared here for the first time, and 2-phenylbenzothiophene 29. For 12 and 13, initial cyclisation is followed by intramolecular addition and aromatisation to give the tricyclic products 31 and 32, while for 14 intramolecular homolytic substitution leads to the tetracyclic benzonaphthofuran 34 and, by rearrangement, to the isomer 37. Fully assigned 13C NMR spectra are presented for all seven ylides.

Flash Vacuum Pyrolysis of Stabilised Phosphorous Ylides. Part 6. Pyrolysis of Substituted Cinnamoyl Ylides as a Route to Conjugated Enynes

The substituted cinnamoyl ylides 6 and 7, readily prepared in one step from the quaternary phosphonium salts 8 and cinnamoyl chlorides 9, undergo extrusion of Ph3PO upon FVP to give the 1,3-enynes 12 and 13 in moderate yield.At 500 deg C there is little double bond isomerisation, but at 700 deg C this does occur to give almost 1:1 mixtures of E and Z isomers.In a few cases, including those with a nitrophenyl group present, the yields are poor or the reactions fail stabilised ylide was only partly successful since the severe conditions required for loss of the ester group resulted in significant isomerisation to naphthalene.The fully assigned 13C NMR spectra for 20 enynes are reported.One examples of the isomeric β,γ-unsaturated-δ-oxo ylides, 14 has been prepared and is found to undergo loss of Ph3P on FVP at 700 deg C to give indene and benzene in low yield.