Cross-coupling reaction of organosilicon nucleophiles
申请人:——
公开号:US20020183516A1
公开(公告)日:2002-12-05
Improved methods for generating a —C—C— bond by cross-coupling of a transferable group with an acceptor group. The transferable group is a substituent of an organosilicon nucleophile and the acceptor group is provided as an organic electrophile. The reaction is catalyzed by a Group 10 transition metal complex (e.g., Ni, Pt or Pd), particularly by a palladium complex. Certain methods of this invention use improved organosilicon nucleophiles which are readily prepared, can give high product yields and exhibit high stereo selectivity. Methods of this invention employ activating ions such as halides, hydroxide, hydride and silyloxides. In specific embodiments, organosilicon nucleophilic reagents of this invention include siloxanes, particularly cyclic siloxanes. The combination of the cross-coupling reactions of this invention with ring-closing metathesis, hydrosilylation and intramolecular hydrosilylation reactions provide useful synthetic strategies that have wide application.
Stereospecific Palladium-Catalyzed Cross-Coupling of (<i>E</i>)- and (<i>Z</i>)-Alkenylsilanolates with Aryl Chlorides
作者:Scott E. Denmark、Jeffrey M. Kallemeyn
DOI:10.1021/ja065988x
日期:2006.12.1
geometrically defined (E)- and (Z)-alkenyl- and styrylsilanolates with a wide variety of aromatic and heteroaromatic chlorides has been achieved. Under catalysis by bulky, biphenyl-derived phosphines and allylpalladium chloride, the (preformed, stable) potassium salts of di-, tri- and tetrasubstituted alkenyldimethylsilanols undergo high yielding and highly stereospecific coupling to aryl chlorides in THF or dioxane
Cross-Coupling Reactions of Alkenylsilanols with Fluoroalkylsulfonates
作者:Scott E. Denmark、Ramzi F. Sweis
DOI:10.1021/ol026900x
日期:2002.10.1
[GRAPHIC]The design and development of an effective protocol for the palladium-catalyzed cross-coupling of (E)- and (Z)-heptenyidimethylsilanois with organo-triflates and nonaflates is described. Optimization of this coupling focused on the issues of both reactivity and stability of the psuedohalides in the presence of the nucleophilic fluoride promoter for the coupling. The crucial role of varying amounts of water to modulate the reactivity of the fluoride ion is highlighted.
Highly Stereospecific, Palladium-Catalyzed Cross-Coupling of Alkenylsilanols
作者:Scott E. Denmark、Daniel Wehrli
DOI:10.1021/ol005565e
日期:2000.2.1
[reaction: see text] Alkenylsilanols bearing methyl ((E)-1 and (Z)-1) or isopropyl ((E)-2 and (Z)-2)) substituents are converted to disubstituted alkenes by a palladium(0)-catalyzedcross-coupling reaction with aryl or vinyl iodides in the presence of tetrabutylammonium fluoride or hydroxide. Yields and stereoselectivities are generally high, and the reaction is compatible with a wide range of functional