Bromoform Activation. TiCl4–Mg-Promoted CHBr2– and CBr3– Transfer to a Variety of Aldehydes and Ketones
摘要:
TiCl4-Mg can mediate addition of CHBr3 to a variety of aldehydes and ketones to form dibromomethyl carbinols and also be used to effect CBr3 transfer to carbonyl groups to form tribromomethyl carbinols. The successful application of TiCl4-Mg-promoted coupling of CHBr3 with various carbonyl compounds, especially in the case of highly enolizable ketones such as 2-indanone and beta-tetralone, highlights the extraordinary reactivity and selectivity and the weakly basic nature of this system.
Verfahren zur Herstellung substituierter gamma-Halogencarbonsäureester
申请人:BAYER AG
公开号:EP0005472A2
公开(公告)日:1979-11-28
Die vorliegende Erfindung betrifft ein Verfahren zur Herstellung von y-Halogen-carbonsäureestern der Formel (IV)
in welcher R1-R8 die in der Beschreibung angegebene Bedeutung besitzen durch Umsetzung einer Verbindung dei Formel (V)
mit einem Orthoester der Formel (VI)
oder mit einem Ketnaceta der Forme! (VII)
dadurch gekennzeichnet, daß man das bei dieser Umsetzung erhaltene Gemisch mit maximal 1 Moläquivalent eines Halogenierungsmittels behandelt. r
Bromoform Activation. TiCl<sub>4</sub>–Mg-Promoted CHBr<sub>2</sub><sup>–</sup> and CBr<sub>3</sub><sup>–</sup> Transfer to a Variety of Aldehydes and Ketones
作者:Tu-Hsin Yan、Su-Haur Chang、Cheng-Ta Chang、Chia-Kuan Lin、Chien-Yu Liu
DOI:10.1021/ol402861a
日期:2013.11.15
TiCl4-Mg can mediate addition of CHBr3 to a variety of aldehydes and ketones to form dibromomethyl carbinols and also be used to effect CBr3 transfer to carbonyl groups to form tribromomethyl carbinols. The successful application of TiCl4-Mg-promoted coupling of CHBr3 with various carbonyl compounds, especially in the case of highly enolizable ketones such as 2-indanone and beta-tetralone, highlights the extraordinary reactivity and selectivity and the weakly basic nature of this system.