Rh<sub>2</sub>
(<i>S</i>
-1,2-NTTL)<sub>4</sub>
: A Novel Rh<sub>2</sub>
(<i>S</i>
-PTTL)<sub>4</sub>
Analog With Lower Ligand Symmetry for Asymmetric Synthesis of Chiral Cyclopropylphosphonates
作者:Frady G. Adly、Johncarlo Maddalena、Ashraf Ghanem
DOI:10.1002/chir.22349
日期:2014.11
2‐naphthaloyl‐(S)‐amino acid ligands. In terms of enantioselectivity, Rh2(S‐1,2‐NTTL)4 (3a) derived from N‐1,2‐naphthaloyl‐(S)‐tert‐leucine, was the best‐performing catalyst among the new series in the enantioselective synthesis of cyclopropylphosphonate derivatives (up to >99% enantiomeric excess). A predictive model was proposed to justify the observed high enantiomeric induction exhibited by Rh2(S‐1,2‐NTTL)4
Design and Synthesis of Novel Chiral Dirhodium(II) Carboxylate Complexes for Asymmetric Cyclopropanation Reactions
作者:Frady G. Adly、Michael G. Gardiner、Ashraf Ghanem
DOI:10.1002/chem.201504817
日期:2016.3.1
the design of dirhodium(II) tetracarboxylates derived from (S)‐amino acid ligands is reported. The approach is founded on tailoring the steric influences of the overall catalyst structure by reducing the local symmetry of the ligand's N‐heterocyclic tether. The application of the new approach has led to the uncovering of [Rh2(S‐tertPTTL)4] as a new member of the dirhodium(II) family with extraordinary
[EN] DIRHODIUM COMPOUNDS AND METHODS OF USE<br/>[FR] COMPOSÉS DE DIRHODIUM ET PROCÉDÉS D'UTILISATION
申请人:GHANEM ASHRAF
公开号:WO2016037223A1
公开(公告)日:2016-03-17
The present invention is directed to dirhodium compounds and their use as catalysts in stereoselective syntheses. In particular, the dirhodium catalysts include ligands comprising substituted cyclic imide protected amino acids. The use of the dirhodium catalysts in reactions that proceed via a rhodium carbene or nitrene intermediate is also described.
Switchable Synthesis of 3-Substituted 1<i>H</i>-Indazoles and 3,3-Disubstituted 3<i>H</i>-Indazole-3-phosphonates Tuned by Phosphoryl Groups
作者:Guihua Chen、Minglin Hu、Yungui Peng
DOI:10.1021/acs.joc.7b02857
日期:2018.2.2
3-alkyl/aryl-3H-indazole-3-phosphonates were synthesized efficiently through a 1,3-dipolarcycloadditionreaction between α-substituted α-diazomethylphosphonates and arynes under simple reaction conditions. The product distribution was controlled by the phosphoryl group, which acted both as a tuning group and a traceless group in the reaction.
Asymmetric [3+2] Cycloaddition Reactions of α‐Substituted Diazophosphonates with 3‐Acryloyl‐2‐oxazolidinone to Access Chiral Pyrazoline Derivatives with Phosphonyl at a Tetrasubstituted Stereogenic Center
An efficient asymmetric 1,3‐dipolar cycloaddition reaction between α‐substituted diazophosphonates and 3‐acryloyl‐2‐oxazolidinone, catalyzed by a chiral Mg(II)/BOX complex, has been achieved for the first time. This reaction gave the corresponding chiral 5,5‐disubstituted 1H‐pyrazoline‐5‐phosphonates in good yields (up to 98%) and excellent stereoselectivities (up to 95% ee). The resulting highly functionalized