Synthesis of Benzyl-, Allyl-, and Allenyl-boronates via Copper-Catalyzed Borylation of Alcohols
作者:Lujia Mao、Kálmán J. Szabó、Todd B. Marder
DOI:10.1021/acs.orglett.7b00256
日期:2017.3.3
Alcohols are among the most abundant and readily available organic feedstocks in industrial processes. The direct catalytic functionalization of sp3 C–O bonds of alcohols remains the main challenge in this field. Here, we report a copper-catalyzed synthesis of benzyl-, allyl-, and allenyl-boronates from benzylic, allylic, and propargylic alcohols, respectively. This protocol exhibits a broad reaction
Zn(OH)2-catalyzed allylation reactions of allylboronates with aldehydes proceeded smoothly in aqueous media; when α-substituted allylboronates were employed, the α-addition products were obtained exclusively, and syn-adducts were formed selectively in most cases; the use of Zn(OH)2 with dmp (ligand) in aqueous media is the key to these reactions.
Zn-Catalyzed Asymmetric Allylation for the Synthesis of Optically Active Allylglycine Derivatives. Regio- and Stereoselective Formal α-Addition of Allylboronates to Hydrazono Esters
have developed Zn-catalyzed asymmetricallylation of hydrazonoesters with allylboronates. The reactions proceeded smoothly in high yields and high stereoselectivities. Remarkably, formal α-addition occurred for α-substituted allylboronates exclusively, and excellent stereoselectivities were observed. This is the first example of catalytic regio- and stereoselective allylations with formal α-addition.
Rh‐Catalyzed Coupling of Aldehydes with Allylboronates Enables Facile Access to Ketones
作者:Kezhuo Zhang、Jiaxin Huang、Wanxiang Zhao
DOI:10.1002/chem.202103851
日期:2022.3.10
A novel strategy for the preparation of ketones from aldehydes and allylic boronic esters is presented. This reaction involves the allylation of aldehydes with allylic boronic esters and the Rh-catalyzed chain-walking of homoallylic alcohols. This approach features mild reaction conditions, broad substrate scope, and excellent functional groups. Mechanistic studies also supported that a tandem allylation