Readily Accessible Chiral Diene Ligands for Rh-Catalyzed Enantioselective Conjugate Additions of Boronic Acids
作者:Barry M. Trost、Aaron C. Burns、Thomas Tautz
DOI:10.1021/ol201754c
日期:2011.9.2
the broad scope of the Pd-catalyzed asymmetric alkylation of meso- and d,l-divinylethylene carbonate, several chiral diene ligands were prepared in two steps from commercial materials. Subsequently, these ligands were evaluated in the Rh-catalyzed asymmetric conjugateaddition of boronic acids to enones.
A Chiral Bis-Sulfoxide Ligand in Late-Transition Metal Catalysis; Rhodium-Catalyzed Asymmetric Addition of Arylboronic Acids to Electron-Deficient Olefins
A bis-sulfoxide with a binaphthyl backbone is introduced as a readily available, chiralligand entity in late-transition metal catalysis. Ligand p-tol-BINASO [where p-tol-BINASO is 1,1‘-binaphthalene-2,2‘-diyl-bis-(p-tolylsulfoxide)] is obtained in pure form in one single synthetic step from relatively cheap, commercially available starting materials. Precatalyst [(P,R,R)-p-tol-BINASO}RhCl]2 was synthesized
it both ways: A novel class of chiral sulfoxide‐olefin ligands was synthesized from a single chiral source. These ligands were evaluated in rhodium‐catalyzed 1,4‐additions of arylboronic acids to electron‐deficient olefins, and remarkable olefin‐directed reversal of stereoselectivity (up to >99 % ee, R isomer; 98 % ee, S isomer) was observed when the reversal ligand pair L1 (branched olefin) and L2
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
A chiral phosphine–olefin ligand derived from l-hydroxyproline and its use in the rhodium-catalyzed asymmetric 1,4-addition
作者:Vasudeva Rao Gandi、Yixin Lu、Tamio Hayashi
DOI:10.1016/j.tetasy.2015.05.004
日期:2015.7
A new chiralphosphine–olefinligand (S)-1 has been designed and synthesized from l-hydroxyproline via a short reaction sequence. It was examined for its efficiency in the rhodium-catalyzedasymmetric addition of arylboronic acids and a phenylzinc reagent to cyclic α,β-unsaturated ketones, giving 1,4-addition products with high enantioselectivities.