58926-23-1Relevant articles and documents
A practical, large-scale synthesis of pyrene-2-carboxylic acid
Casas-Solvas, Juan M.,Mooibroek, Tiddo J.,Sandramurthy, Shugantan,Howgego, Joshua D.,Davis, Anthony P.
, p. 2591 - 2594 (2014)
Pyrene-2-carboxylic acid is a versatile intermediate for introducing the unusual 2-pyrenyl unit into functional organic molecules. A classical preparation for this molecule has been revised and improved to give a robust and efficient three-step process. The method has been applied on a multigram scale to give pyrene-2-carboxylic acid in >70% overall yield from pyrene.
The Size-Accelerated Kinetic Resolution of Secondary Alcohols
P?lloth, Benjamin,Sibi, Mukund P.,Zipse, Hendrik
supporting information, p. 774 - 778 (2020/12/01)
The factors responsible for the kinetic resolution of alcohols by chiral pyridine derivatives have been elucidated by measurements of relative rates for a set of substrates with systematically growing aromatic side chains using accurate competitive linear regression analysis. Increasing the side chain size from phenyl to pyrenyl results in a rate acceleration of more than 40 for the major enantiomer. Based on this observation a new catalyst with increased steric bulk has been designed that gives enantioselectivity values of up to s=250. Extensive conformational analysis of the relevant transition states indicates that alcohol attack to the more crowded side of the acyl-catalyst intermediate is favoured due to stabilizing CH-π-stacking interactions. Experimental and theoretical results imply that enantioselectivity enhancements result from accelerating the transformation of the major enantiomer through attractive non-covalent interactions (NCIs) rather than retarding the transformation of the minor isomer through repulsive steric forces.
