Endo‐type cross‐conjugated trienamines between highly congested α′‐alkylidene 2‐cyclohexenones and a chiral primary amine catalyst serve as HOMO‐raised dienophiles in inverse‐electron‐demand aza‐Diels–Alder cycloadditions with a number of 1‐azadiene substrates. The reactions exhibit exclusive β,γ‐regioselectivity, and multifunctional products with high molecular complexity are efficiently constructed
Modified cinchona alkaloid-catalysed enantioselective [4+4] annulations of cyclobutenones and 1-azadienes
作者:Bo Jiang、Wei Du、Ying-Chun Chen
DOI:10.1039/d0cc02836c
日期:——
An asymmetric [4+4] annulation reaction between β-substituted cyclobutenones and diverse 1-azadienes is developed under the catalysis of modified cinchona alkaloids.
On heating 3-cyano-l-aza-l,3-dienes 5, 6 and 9 with diphenylketene, [4+2] cycloaddition took place smoothly to afford the corresponding piperidin-2-one derivatives 7, 8 and 10 in high yields, respectively.