3742-75-4Relevant articles and documents
Nickel-Catalyzed Decarboxylative Coupling of Redox-Active Esters with Aliphatic Aldehydes
Xiao, Jichao,Li, Zhenning,Montgomery, John
supporting information, p. 21234 - 21240 (2021/12/27)
The addition of alkyl fragments to aliphatic aldehydes is a highly desirable transformation for fragment couplings, yet existing methods come with operational challenges related to the basicity and instability of the nucleophilic reagents commonly employed. We report herein that nickel catalysis using a readily available bioxazoline (BiOx) ligand can catalyze the reductive coupling of redox-active esters with aliphatic aldehydes using zinc metal as the reducing agent to deliver silyl-protected secondary alcohols. This protocol is operationally simple, proceeds under mild conditions, and tolerates a variety of functional groups. Initial mechanistic studies suggest a radical chain pathway. Additionally, alkyl tosylates and epoxides are suitable alkyl precursors to this transformation providing a versatile suite of catalytic reactions for the functionalization of aliphatic aldehydes.
Manganese-Catalyzed Stereospecific Hydroxymethylation of Alkyl Tosylates
Shenouda, Hannah,Alexanian, Erik J.
supporting information, p. 9268 - 9271 (2019/11/19)
The development of a stereospecific hydroxymethylation of alkyl tosylates using an inexpensive, first-row catalyst is described. The transformation proceeds under mild conditions with low pressure to deliver homologated alcohols as products. Chiral, nonracemic β-branched primary alcohols are obtained with high enantiospecificity from easily accessed secondary alkyl substrates. Simple modification of the reaction system also permits access to α-d2 alcohols. These studies use anionic metal carbonyl catalysis to access a synthetic equivalent of the challenging hydroxymethyl anion from carbon monoxide.
Fast and reliable generation of [18F]triflyl fluoride, a gaseous [18F]fluoride source
Pees,Sewing,Vosjan,Tadino,Herscheid,Windhorst,Vugts
supporting information, p. 10179 - 10182 (2018/09/13)
A novel strategy for the production of reactive [18F]fluoride has been developed, omitting time consuming azeotropic drying procedures. Gaseous [18F]triflyl fluoride is formed instantaneously at room temperature from hydrated [18F]fluoride, followed by distillation in less than 5 minutes into a dry aprotic solvent, in which dry [18F]fluoride is released in presence of base with >90% radiochemical yield. The reactivity of the [18F]fluoride has been confirmed by reaction with several model compounds and by the synthesis of the PET tracers [18F]fluoroestradiol ([18F]FES) and O-2-[18F]fluoroethyl-l-tyrosine ([18F]FET), providing good isolated radiochemical yields and molar activities of up to 123 GBq μmol?1.
