1040384-68-6Relevant articles and documents
Synthesis of novel carbohydrate-based iminophosphinite ligands in Pd-catalyzed asymmetric allylic alkylations
Shen, Chao,Xia, Haijun,Zheng, Hui,Zhang, Pengfei,Chen, Xinzhi
, p. 1936 - 1941 (2010)
A series of novel carbohydrate-based iminophosphinite ligands have been synthesized for the first time and successfully applied in Pd-catalyzed asymmetric allylic alkylation. The substituent effects on the catalytic reaction were also investigated, and 92% ee was achieved when the p-nitro-substituted ligand 10d was used.
Modular phosphite-oxazoline/oxazine ligand library for asymmetrie Pd-catalyzed allylic substitution reactions: scope and limitations - origin of enantioselectivity
Dieguez, Montserrat,Pamies, Oscar
experimental part, p. 3653 - 3669 (2009/04/23)
A library of phosphite-oxazoline/oxazine ligands L1-L15a-h has been synthesized and screened in the Pd-catalyzed allylic substitution reactions of several substrate types. These series of ligands can be prepared efficiently from easily accessible hydroxyl amino acid derivatives. Their modular nature enables the substituents/configurations in the oxazoline/oxazine moiety, alkyl backbone chain and in the biaryl phosphite moiety to be easily and systematically varied. By carefully selecting the ligand components, therefore, high regio- and enantioselectivities (ee values up to 99%) and good activities have been achieved in a broad range of mono- and disubstituted linear hindered and unhindered liner and cyclic substrates. The NMR studies on the Pd-π-allyl intermediates provide a deeper understanding about the effect of the ligand parameters on the origin of enantioselectivity. It also indicates that the nucleophilic attack takes place predominantly at the allylic terminal carbon atom located trans to the phosphite moiety.
