cycloalkanes have been reported. Zard reported an example of a two-step procedure involving xanthate transfer radicaladdition to a vinyl MIDA boronate, followed by an intramolecular homolyticaromaticsubstitution reaction on a thiophene.21 Norton and coll. reported an interesting cobaloxime catalyzed radical cycloisomerization process leading to borylated 5-membered rings (Scheme 1, B). Lin et al. reported
Formal Regiocontrolled Hydroboration of Unbiased Internal Alkynes via Borylation/Allylic Alkylation of Terminal Alkynes
作者:Abraham L. Moure、Pablo Mauleón、Ramón Gómez Arrayás、Juan Carlos Carretero
DOI:10.1021/ol4007663
日期:2013.4.19
boronates from terminalalkynes, a propargyl directing (2-pyridyl)sulfonyl group allows terminalalkynes to undergo Cu-catalyzed B2(pin)2-borylation and subsequent Cu-catalyzed allylic alkylation with Grignard reagents without affecting the pinacolboronate moiety, thereby formally enabling a highly stereo- and regiocontrolled access to hydroboration products of unbiased dialkyl internal alkynes.