Up-Scale Synthesis of p -(CH 2 =CH)C 6 H 4 CH 2 CH 2 CH 2 Cl and p -ClC 6 H 4 SiR 3 by CuCN-Catalyzed Coupling Reactions of Grignard Reagents with Organic Halides.

Grignard reagents featuring carbanion characteristics are mostly unreactive toward alkyl halides and require a catalyst for the coupling reaction. With the need to prepare p -(CH 2 =CH)C 6 H 4 CH 2 CH 2 CH 2 Cl on a large scale, the coupling reaction of p -(CH 2 =CH)C 6 H 4 MgCl with BrCH 2 CH 2 CH 2 Cl was attempted to screen the catalysts, and CuCN was determined to be the best catalyst affording the desired compound in 80% yield with no formation of Wurtz coupling side product CH 2 =CHC 6 H 4 -C 6 H 4 CH=CH 2 . The p -(CH 2 =CH)C 6 H 4 Cu(CN)MgCl species was proposed as an intermediate based on the X-ray structure of PhCu(CN)Mg(THF) 4 Cl. p -ClC 6 H 4 MgCl did not react with sterically encumbered R 3 SiCl (R = n -Bu or n -octyl). However, the reaction took place with the addition of 3 mol % CuCN catalyst, affording the desired compound p -ClC 6 H 4 SiR 3 . The structures of p -(CH 2 =CH)C 6 H 4 CH 2 CH 2 CH 2 MgCl and p -ClC 6 H 4 MgCl were also elucidated, which existed as an aggregate with MgCl 2 , suggesting that some portion of the Grignard reagents were possibly lost in the coupling reaction due to coprecipitation with the byproduct MgCl 2 . R 3 SiCl (R = n -Bu or n -octyl) was also prepared easily and economically with no formation of R 4 Si when SiCl 4 was reacted with 4 equiv of RMgCl. Using the developed syntheses, [ p -(CH 2 =CH)C 6 H 4 CH 2 CH 2 CH 2 ] 2 Zn and iPrN[P(C 6 H 4 - p -SiR 3 ) 2 ] 2 , which are potentially useful compounds for the production of PS- block -PO- block -PS and 1-octene, respectively, were efficiently synthesized with substantial cost reductions.