Boryl-Dictated Site-Selective Intermolecular Allylic and Propargylic C-H Amination was written by Liu, Yuan;Chen, Zhi-Hao;Li, Yin;Qian, Jiasheng;Li, Qingjiang;Wang, Honggen. And the article was included in Journal of the American Chemical Society in 2022.SDS of cas: 252288-04-3 This article mentions the following:
For internal alkenes possessing two or more sets of electronically and sterically similar allylic protons, the site-selectivity for allylic C-H functionalization is fundamentally challenging. Previously, the neg. inductive effect from an electroneg. atom is effective for several inspiring regioselective C-H functionalization reactions. Yet, the use of an electropos. atom for a similar purpose remains to be developed. α-Aminoboronic acids and their derivatives found widespread applications. Their current syntheses rely heavily on functional group manipulations. Herein the authors report a boryl-directed intermol. C-H amination of allyl N-methyliminodiacetyl boronates (B(MIDA)s) and propargylic B(MIDA)s to give α-amino boronates with an exceptionally high level of site-selectivities (up to 300:1). A wide variety of highly functionalized secondary and tertiary α-amino boronates are formed in generally good to excellent yields, thanks to the mildness of the reaction conditions. The unsaturated double and triple bonds within the product leave room for further decorations. Mechanistic studies reveal that the key stabilization effect of the B(MIDA) moiety on its adjacent developing pos. charge is responsible for the high site-selectivity and that a closed transition state might be involved, as the reaction is fully stereoretentive. An activation effect of B(MIDA) is also found. In the experiment, the researchers used many compounds, for example, (11bS)-N,N-Diethyldinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepin-4-amine (cas: 252288-04-3SDS of cas: 252288-04-3).
(11bS)-N,N-Diethyldinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepin-4-amine (cas: 252288-04-3) belongs to chiral phosphine ligands. At present, the synthesis of new chiral phosphines designed specifically for nucleophilic organocatalysis remains a significant challenge. Effective chiral catalysts for nucleophilic phosphine catalysis are scarce, seriously limiting the development of asymmetric variants. SDS of cas: 252288-04-3
Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis