The author of 《Total synthesis of indolizidine alkaloid (-)-209D: overriding substrate bias in the asymmetric rhodium-catalyzed [2+2+2] cycloaddition》 were Yu, Robert T.; Lee, Ernest E.; Malik, Guillaume; Rovis, Tomislav. And the article was published in Angewandte Chemie, International Edition in 2009. Recommanded Product: 329735-68-4 The author mentioned the following in the article:
The use of chiral biphenyl-based phosphoramidite ligands on rhodium provides an efficient [2+2+2] cycloaddition between terminal alkyl alkynes, e.g. 1-octyne, and alkenyl isocyanates, e.g. H2C:CH(CH2)3NCO. The cycloaddition proceeds through a CO migration pathway, and facilitates a rapid four-step asym. synthesis of indolizidine (-)-209D (I). In the experiment, the researchers used (R)-3,3′-Di-tert-butyl-5,5′,6,6′-tetramethylbiphenyl-2,2′-diol(cas: 329735-68-4Recommanded Product: 329735-68-4)
(R)-3,3′-Di-tert-butyl-5,5′,6,6′-tetramethylbiphenyl-2,2′-diol(cas: 329735-68-4) belongs to phenols. Phenols are more acidic than typical alcohols.Recommanded Product: 329735-68-4 The acidity of the hydroxyl group in phenols is commonly intermediate between that of aliphatic alcohols and carboxylic acids (their pKa is usually between 10 and 12).
Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts