1046468-79-4Relevant academic research and scientific papers
Nickel-catalyzed Mizoroki-Heck reaction of aryl sulfonates and chlorides with electronically unbiased terminal olefins: High selectivity for branched products
Tasker, Sarah Z.,Gutierrez, Alicia C.,Jamison, Timothy F.
supporting information, p. 1858 - 1861 (2014/03/21)
Achieving high selectivity in the Heck reaction of electronically unbiased alkenes has been a longstanding challenge. Using a nickel-catalyzed cationic Heck reaction, we were able to achieve excellent selectivity for branched products (≥19:1 in all cases) over a wide range of aryl electrophiles and aliphatic olefins. A bidentate ligand with a suitable bite angle and steric profile was key to obtaining high branched/linear selectivity, whereas the appropriate base suppressed alkene isomerization of the product. Although aryl triflates are traditionally used to access the cationic Heck pathway, we have shown that, by using triethylsilyl trifluoromethanesulfonate, we can effect a counterion exchange of the catalytic nickel complex, such that cheaper and more stable aryl chlorides, mesylates, tosylates, and sulfamates can be used to yield the same branched products with high selectivity. Branching out: A Ni-catalyzed Heck reaction for the preparation of 1,1-disubstituted alkenes is presented. High selectivity for the branched products is achieved with electronically unbiased aliphatic terminal olefins. Regioselectivities remain consistently high (≥19:1) throughout. TESOTf=triethylsilyl trifluoromethanesulfonate. Copyright
