Catalytic asymmetric oxo-Diels–Alder reactions with chiral atropisomeric biphenyl diols

Abstract

New chiral atropisomeric biphenyl diols 3, 4 and 6 containing additional peripheral chiral centers with different steric bulkiness and/or electronic properties were synthesized. The X-ray crystal structure of 3 shows the formation of a supramolecular structure whereas that of 6, containing additional CF3 substituents, shows the formation of a monomeric structure. Diols 1–6 were found to be active organocatalysts in oxo-Diels–Alder reactions in which 2 recorded a 72% ee with trimethylacetaldehyde as a substrate.

Facially Selective Oxo-Diels-Alder Cycloadditions of α-Dienyl-β-Lactam: An Entry to Pyrano Tethered β-Lactams Bifunctional Hybrids

“…[6][7][8] Different variants of HDA reactions have been explored for a highly efficient stereoselective [9][10][11][12][13] synthesis of six-membered ring compounds. Of these, oxo-Diels-Alder (ODA) [14][15][16][17][18] variant has considerable potential because of the tactical formation of a variety of six membered derivatives such as dihydropyrans, dihydropyrones etc.…”