307002-86-4

Upstream product

• 80522-42-5 triisopropylsilyl trifluoromethanesulfonate 
• 307002-78-4 4,4-dimethyl-7-phenylhept-1-en-6-yn-3-ol 
• 23151-06-6 2,2-dimethyl-pent-4-ynal 
• 109433-06-9 4,4-dimethylhept-1-en-6-yn-3-ol 
• 591-50-4 iodobenzene 
• 197963-29-4 2,2-dimethyl-5-phenylpent-4-ynal 

Relevant academic research and scientific papers

endo-selective intramolecular Pauson - Khand reactions of γ-oxygenated-αβ-unsaturated phenylsulfones

A wide variety of 1,6-enynes and 1,7-enynes incorporating γ-oxygenated-α,β-unsaturated phenylsulfone moieties have readily been prepared by piperidine-promoted condensation of the corresponding alkynyl aldehyde with phenylsulfonyl-(p-tolylsulfinyl)methane and further protection of the hydroxyl group. Despite the enduring claim concerning the unsuitability of electronically deficient olefins in Pauson - Khand reactions, we report that these 1-sulfonylated enynes are excellent substrates in intramolecular Pauson - Khand reactions under both thermal and amine N-oxide-promoted conditions. Moreover, in contrast with the usual exo-selective Pauson - Khand cyclization of allylic substituted enynes, the reactions of these 1-sulfonylated-3-oxygenated enynes occur with a moderate or high endo selectivity. The evaluation of the chemical and stereochemical scope of the process in comparison with the Pauson - Khand cyclization of non-sulfonylated enynes, its application to the stereo-selective preparation of optically pure C6-substituted bicyclo[3.3.0]oct-1-en-3-ones, and the interpretation of the stereochemical outcome are also discussed.