The Negishi Protocol

Alkynylzinc reagents generally feature a higher intrinsic reactivity for crosscoupling than alkynylstannanes that are used in the Stille coupling. In spite of the 

R = aryl, vinyl, acyl R = aryl, vinyl, alkyl, etc. 

On the basis of the Negishi protocol, C(sp)-C(sp) cross-couplings between alkynylzinc reagents and iodoalkynes have been developed as a mild and copper-free alternative to traditional protocols such as the Stephens-Castro or the Cadiot-Chodkiewicz [272]. 

An operationally simple and efficient method for the construction of C(sp) -C(sp ) bonds from terminal alkynes and alkylzinc reagents by Pd-catalyzed oxidative 

---

Transition metal-catalyzed polymerizations have been reported to give high-purity, regioregular poly-3-alkylthio-phenes suitable for use in electronic devices. Thus, the Negishi protocol using a nickel catalyst and Rieke zinc was employed for the polymerization of 63 to produce the product as a low molecular weight polymer <2003CC2548>. 

E. Negishi, Overview of the Negishi Protocol with Zn, Al, Zr, and Related Metals, in Handbook of Organopalladiiun Chemistry for Organic Synthesis , ed. E. Negishi, John Wiley and Sons, Hoboken, NJ, 2002, p. 229. Editor. 

III.2.1 Overview of the Negishi Protocol with Zn, Al, Zr, and Related Metals... 

B. VARIOUS OTHER FACTORS AND PARAMETERS FOR THE COMPARISON OF THE NEGISHI PROTOCOL WITH OTHER PROTOCOLS... 

Negishi E-i (2002) Overview of the Negishi protocol with Zn, Al, Zr, and related metals. In Negishi E-i, de Meijere A (eds) Handbook of organopalladium chemistry for organic synthesis. Wiley, New York... 

As mentioned earlier, one of the most significant applications of a-lithiation chemistry has been its utility in a-arylations. Dieter and Li have extended the a-arylation method to racemic 2-lithio-N-Boc piperidines using the combination of copper cyanide and palladium(O), albeit with the same substrate scope as noted for pyrrolidines vide supra). Coldham and Leonori applied the Negishi protocol to AT-Boc piperidine which gave access to a wider range of racemic 2-arylpiperidines (Scheme 11.33). ... 

---