Palladium-Catalyzed Asymmetric Conjugate Addition of Arylboronic Acids to Heterocyclic Acceptors
作者:Jeffrey C. Holder、Alexander N. Marziale、Michele Gatti、Bin Mao、Brian M. Stoltz
DOI:10.1002/chem.201203643
日期:2013.1.2
Flava Flavanone: Asymmetricconjugateadditions to chromones and 4‐quinolones are reported utilizing a single catalyst system formed in situ from Pd(OCOCF3)2 and (S)‐tBuPyOX. Notably, these reactions are performed in wet solvent under ambient atmosphere, and employ readily available arylboronicacids as the nucleophile, thus providing ready access to these asymmetric heterocycles (see scheme).
Enantioselective Synthesis of Azaflavanones Using Organocatalytic 6-<i>endo</i>Aza-Michael Addition
作者:Shuanghua Cheng、Lili Zhao、Shouyun Yu
DOI:10.1002/adsc.201300920
日期:2014.3.24
A method to prepare highly enantioenriched azaflavanonesusing an organocatalytic 6‐endo aza‐Michael addition has been described. A variety of 2‐aryl‐, 2‐vinyl‐ and 2‐methylazaflavanones were prepared in good yields (53–84%) and excellent enantioselectivities (97.6:2.4 to 99.3:0.7 er).
Rhodium-Catalyzed Enantioselective Conjugate Addition of Sodium Tetraarylborates to 2,3-Dihydro-4-pyridones and 4-Quinolones by Using (R,R)-1,2-Bis(tert-butylsulfinyl)benzene as a Ligand
(R,R)-1,2-Bis(tert-butylsulfinyl)benzene as an efficient and simple ligand can be applied in the rhodium-catalyzed asymmetric 1,4-addition of sodiumtetraarylborate reagents to N-substituted 2,3-dihydro-4-pyridones and 4-quinolones. The reactions proceeded smoothly to provide the corresponding adducts in good yields (up to 92%) and excellent enantioselectivities (up to 99% ee) under mild conditions