Heck-Hiyama reaction

Hiyama and co-workers have reported that the Mizoroki-Heck-type reaction of aryl- and alkenylsilanols is efficiently promoted by a Pd(OAc)2/Cu(OAc)2/LiOAc system (Equation (9)).50 50a in contrast, a dicationic Pd(ll) complex prepared in situ from Pd(dba)2, a diphosphine (dppe or dppben), and Cu(BF4)2 catalyzes 1,4-addition of aryltrialkoxysilanes to a-enones and a-enals in aqueous media (Equation (10)).51 The Pd-catalyzed 1,4-addition of the arylsilanes can be achieved also by using excess amounts of TBAF 3H20, SbCl3, and acetic acid.52... 

Hiyama and Mori introduced the Mizoroki-Heck-type reaction of aryl- and vinyl-... 

These reactions are Moritani-Fujiwara reactions, Heck reactions, Mizoroki-Heck reactions, Kumada-Tamao-Corriu reactions, Murahashi reactions, Eto-Hagihara reactions, Negishi reactions, Migita-Kosugi-Stille reactions, Suznki-Miyanra reactions, and Hiyama reactions. 

Transmetallation of alkenylsilanes takes place with retention of the double bond configuration, as in other cross-coupling reactions [295]. Owing to the lower transmetallation rate, competing 1,2-insertion of the alkene in the intermediate organopalladium complex (as a Heck type reaction) may take place, which affects the regioselectivity of the Hiyama reaction in some cases (Scheme 1.38) [296]. This... 

Scheme 1.38 The Hiyama reaction involving alkene insertion (as a Heck type reaction) before transmetallation.

SCHEME 19.50 Heck followed by Hiyama reactions in the synthesis of nitidine [68]. 

Grigg and coworkers developed bimetallic domino reactions such as the electro-chemically driven Pd/Cr Nozaki-Hiyama-Kishi reaction [69], the Pd/In Barbier-type allylation [70], Heck/Tsuji-Trost reaction/1,3 dipolar cycloaddition [71], the Heck reaction/metathesis [72], and several other processes [73-75]. A first example for an anion capture approach, which was performed on solid phase, is the reaction of 6/1-134 and 6/1-135 in the presence of CO and piperidine to give 6/1-136. Liberation from solid phase was achieved with HF, leading to 6/1-137 (Scheme 6/1.30) [76]. 

Chapter 5 includes complete coverage of the transition metals-mediated carbon-carbon bond forming reactions. Pd-, Ni-, Cr-, Zr- and Cu-catalyzed reactions such as Heck, Negishi, Sonogashira, Suzuki, Hiyama, Stille, Kumada reactions are covered in adequate details including the applications of these reactions in organic synthesis. 

Scheme 3.39 Some of the most important cross-coupling reactions catalyzed by Pd (i)Suzuki-Miyaura, (ii) Heck-Mizoroki, (iii) Sonogashira, (iv) Hiyama, and (v) Stille.

Scheme 2.104)." Without the activating reagent, the carbon-silicon bond of a vinyl silane 2324 proved to be inert, and a Heck reaction with aryl iodide 2326 occurred. A second aryl group could then be introduced by Hiyama coupling with iodide 2326 in the presence of an activator. 

The final chapter is devoted to the applications of metals in organic synthesis and will rely on the concepts developed in other parts of the book. We will summarize the various catalytic means of forming carbon-carbon bonds and in particular the use of palladium (Tsuji-Trost, Heck, Sonoganishara, Suzuki, Stille, Hiyama, Corriu-Kumada and animation reactions) and condensations of alkynes (Vollhardt s trimerization and Pauson-Khand reaction). 

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