Polymethylhydrosiloxane (PMHS) as an Additive in Sonogashira Reactions
作者:Robert E. Maleczka Jr.、William P. Gallagher
DOI:10.1055/s-2003-37522
日期:——
Polymethylhydrosiloxane (PMHS) in combination with CsF facilitates the Sonogashira reaction of a variety of alkynes and electrophiles. These couplings appear to involve the in situ formation and reaction of an alkynylsiloxane. Such couplings can be run amine free at room temperature, reaction times are short, workup is easy, and product purification is straightforward. Thus, the advantages (and disadvantages) of running Sonogashira couplings with 1-silylalkynes are realized, without the need to preform the alkynyl silane.
PMHS-Mediated Couplings of Alkynes or Benzothiazoles with Various Electrophiles: Application to the Synthesis of (−)-Akolactone A
作者:William P. Gallagher、Robert E. Maleczka
DOI:10.1021/jo034463+
日期:2003.8.1
Polymethylhydrosiloxane (PMHS) in combination with CsF facilitates the cross-coupling of alkynes or benzothiazoles with an array of vinyl, styryl, and aryl halides or nonaflates as well as acid chlorides. Experimental and spectroscopic evidence indicates that these reactions involve the in situ generation of a siloxyl intermediate. These cross-couplings proceed relatively quickly at room temperature