1194476-52-2Relevant academic research and scientific papers
Copper-catalyzed asymmetric 1,4-hydroboration of coumarins with pinacolborane: Asymmetric synthesis of dihydrocoumarins
Kima, Hyohyun,Yuna, Jaesook
supporting information; experimental part, p. 1881 - 1885 (2010/10/20)
An efficient asymmetric addition of pinacolborane to 4-substituted coumarins proceeded with high enantioselectivity in the presence of a copper(I)-QuinoxP complex as a catalyst to produce the corresponding 1,4-hydroboration products. Treatment of the intermediates with electrophiles, without isolation, resulted in enantioenriched dihydrocoumarins. The utility of this protocol was demonstrated in the formal synthesis of biologically active molecules.
Asymmetric conjugate additions to 1,1′-diactivated cyclic enones-a comparative study
Tang, Xiaoping,Blake, Alexander J.,Lewis, William,Woodward, Simon
experimental part, p. 1881 - 1891 (2010/02/27)
A study of copper-phosphoramidite-catalysed ZnR2 and AlR3 additions to 1,1′-dicarbonyl-activated cyclic Michael acceptors has revealed high enantioselectivities for AlR3 (R = Me, Et) 1,4-addition to a range of 3-acylcoumarins (85-98% ee, trans:cis ～90:10) using commercial or readily available ligands. Large substituents at the 6-position, and to some extent at the 5-position, of the coumarin are less well tolerated, nor is truncation of the coumarin motif to a comparable 2-acylcyclohexenone (ee values up to 78%).
