185-88-6Relevant academic research and scientific papers
trans-Cyclooctenes as Chiral Ligands in Rhodium-Catalyzed Asymmetric 1,4-Additions
Nagano, Tagui,Einaru, Shunsuke,Shitamichi, Kenta,Asano, Keisuke,Matsubara, Seijiro
supporting information, p. 7131 - 7133 (2020/09/11)
trans-Cyclooctenes serve as asymmetric ligands for the rhodium-catalyzed 1,4-additions of organotin reagents to enones. We demonstrate, for the first time, that these chiral olefins can provide efficient coordination spheres for asymmetric metal catalysis. As the asymmetric environment around the reaction site is constructed by the trans-cyclooctene framework, the introduction of a substituent at the allylic position further improves enantioselectivity to 93 % ee. These findings provide new chiral framework designs for the asymmetric ligands of metal catalysts.
Nucleophilic fluoroalkylation of epoxides with fluorinated sulfones
Ni, Chuanfa,Li, Ya,Hu, Jinbo
, p. 6829 - 6833 (2007/10/03)
The unprecedented nucleophilic fluoroalkylation of simple epoxides with fluorinated sulfones was achieved to give the β-fluoroalkyl alcohols in one step. The negative "fluorine effect" in the nucleophilic fluoroalkylation of epoxides with fluorinated carbanions was probed by the reactivity comparison between carbanions PhSO2CF2 - (3) and PhSO2CCl2- (4) and between carbanions PhSO2CHF- (7) and PhSO2CHCl - (13). The mediation of this fluorine effect by introducing another electron-withdrawing benzenesulfonyl group was found to be an effective way to significantly increase the nucleophilicity of the fluorinated carbanions, with the reactivity order [(PhSO2)2CF-] (16) > PhSO2CFH- (7) ? PhSO2CF2 - (3).
ALDEHYDES AND KETONES EPOXIDATION WITH TRIMETHYLSULFONIUM BROMIDE IN A SLIGHTLY HYDRATED SOLID-LIQUID MEDIUM
Bouda, H.,Borredon, M. E.,Delmas, M.,Gaset A.
, p. 503 - 514 (2007/10/02)
Trimethylsulfonium bromide used in low hydrated solid-liquid phase transfer conditions is a very efficient agent for aldehyde and ketone epoxidation.
