Development of P∗-monodentate diamidophosphites with a C1-symmetric 1,2-diamine backbone: the effects of substituents in the 1,3,2-diazaphospholidine cycle on Pd-catalyzed asymmetric allylations
摘要:
We have designed and synthesized a small library of modular monodentate diamidophosphite ligands with stereogenic phosphorus atoms. The library was prepared efficiently from the commercially available and inexpensive (S)-N-Boc-amino acids. These novel ligands were screened in the Pd-catalyzed asymmetric allylations of (E)-1,3-diphenylallyl acetate with dimethyl malonate as the C-nucleophile with up to 93% ee being obtained. The results showed that the different substituents in the 1,3,2-diazaphospholidine cycle had remarkable effects on the enantioselectivity. (c) 2013 Elsevier Ltd. All rights reserved.
Development of P∗-monodentate diamidophosphites with a C1-symmetric 1,2-diamine backbone: the effects of substituents in the 1,3,2-diazaphospholidine cycle on Pd-catalyzed asymmetric allylations
摘要:
We have designed and synthesized a small library of modular monodentate diamidophosphite ligands with stereogenic phosphorus atoms. The library was prepared efficiently from the commercially available and inexpensive (S)-N-Boc-amino acids. These novel ligands were screened in the Pd-catalyzed asymmetric allylations of (E)-1,3-diphenylallyl acetate with dimethyl malonate as the C-nucleophile with up to 93% ee being obtained. The results showed that the different substituents in the 1,3,2-diazaphospholidine cycle had remarkable effects on the enantioselectivity. (c) 2013 Elsevier Ltd. All rights reserved.