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 novel, C2-symmetric, chiral bis-cyclosulfinamide-olefin tridentate ligand in Rh-catalyzed asymmetric 1,4-additions
作者:Li Zhang、Mingchao Tan、Lihong Zhou、Qingle Zeng
DOI:10.1016/j.tetlet.2018.06.008
日期:2018.7
A C2-symmetric, chiral bis-cyclosulfinamide-olefin ligand composed of two 1-oxo-2,3-dihydro-1,2-benzisothiazole moieties with rigid skeletons and a conformationally flexible butenylene chain is disclosed for the first time. HRMS and 1H NMR analyses verify that the in situ-generated complex of the ligand and [Rh(C2H4)2Cl]2 possesses a rhodium (I) center coordinated to the tridentate ligand via two sulfinyl
首次公开了由两个具有刚性骨架和构象柔性的丁烯链的1-氧代-2,3-二氢-1,2-苯并噻唑结构部分组成的AC 2对称的手性双环亚磺酰胺-烯烃配体。HRMS和1 H NMR分析证实,该配体与[Rh(C 2 H 4)2 Cl] 2原位生成的络合物具有通过两个亚磺酰基部分和一个CdbndC键与三齿配体配位的铑(I)中心。手性配体在Rh催化的芳基硼酸与环己烯酮和环戊烯酮的不对称1,4-加成反应中提供了极高的对映选择性(高达> 99%ee)。与类似的手性二齿配体相比,三齿配体具有更高的对映选择性。
Synthesis of Highly Enantioenriched Propelladienes and their Application as Ligands in Asymmetric Rh-Catalyzed 1,4-Additions
作者:Tommaso Pecchioli、Mathias Christmann
DOI:10.1021/acs.orglett.8b02204
日期:2018.9.7
The first synthesis of highly enantioenriched [4.3.3]propelladienes is reported. The novel bridged bicyclo[3.3.0] dienes were applied as steering ligands in the rhodium-catalyzedasymmetric arylation of cyclic enones. The catalytic system showed high catalytic activity, and the 1,4-adducts were obtained in good to excellent yields (46–99%) with enantioselectivities up to 96% ee.
Practical Method for Asymmetric Addition of Arylboronic Acids to α,β-Unsaturated Carbonyl Compounds Utilizing an In Situ Prepared Rhodium Catalyst
作者:Kirill Lukin、Qunying Zhang、M. Robert Leanna
DOI:10.1021/jo802136j
日期:2009.1.16
A new practical method for the asymmetric Michael addition of arylboronic acids to α,β-unsaturated carbonyl compounds utilizing in situ generated chiral rhodium-binap-based catalyst has been developed to address the unavailability of the preformed catalysts. While maintaining high levels of enantioselectivity reported for the preformed catalysts, the new method provides a convenient access to either