Fine‐Tuning the Bicyclo[3.3.1]nona‐2,6‐diene Ligands: Second Generation 4,8‐Substituted Dienes for Rh‐Catalyzed Asymmetric 1,4‐Addition Reactions
作者:Vidmantas Bieliūnas、Sigitas Stončius
DOI:10.1002/cctc.202100638
日期:2021.9.7
C2-symmetric 4,8-endo,endo-bis(alkoxy) bicyclo[3.3.1]nona-2,6-diene ligands possessing additional 4,8-exo,exo substituents is reported. The 4,8-exo,exo groups provide a further element for fine-tuning of the ligand structure by enforcing conformational rigidity of the 4,8-endo,endo side chains. Such tetrasubstituted bicyclo[3.3.1]nona-2,6-dienes were employed as steering ligands in the rhodium-catalyzed arylation
设计和合成了第二代C 2 -对称 4,8-内,内 -双(烷氧基)双环 [3.3.1] 壬 - 2,6-二烯配体,具有额外的 4,8-外,外取代基。4,8- exo,exo基团通过加强 4,8-内、内侧链的构象刚性为配体结构的微调提供了进一步的元素。这种四取代的双环[3.3.1]壬二烯-2,6-二烯在铑催化的环烯酮与芳基硼酸的芳基化反应中被用作导向配体,提供相应的1,4-加成产物,产率良好至极好(69- 99 %) 和高达 99 % ee 的对映选择性。