Organozinc‐Mediated Direct C−C Bond Formation via C−N Bond Cleavage of Ammonium Salts

Abstract

We report a direct cross-coupling reaction between diarylzinc (Ar Zn) and aryltrimethylammonium salts (ArNMe ⋅ OTf) in the presence of LiCl, via C-N bond cleavage. The reaction takes place smoothly upon heating in THF without any external catalyst, enabling an efficient and chemoselective formation of biaryl products. Mechanistic studies indicate that the reaction proceeds through a single electron transfer route.

From Anilines to Aryl Ethers: A Facile, Efficient, and Versatile Synthetic Method Employing Mild Conditions

“…Zuschriften as ar adical scavenger (see Table S1 in the Supporting Information), the yield of 3ad hardly changed, thus excluding radical involvement. [11] Overall, our findings suggest that the current reaction occurs through an S N Ar mechanism, [12] rather than through TM catalysis or ar adical process.D etailed mechanistic studies of this reaction are in progress,using both experimental and theoretical methods. [13] Additional reactions were performed to further examine the scope of this etherification method.…”

Generation of Aryl and Heteroaryl Magnesium Reagents in Toluene by Br/Mg or Cl/Mg Exchange

“…The para-anisylmagnesium derivative 5a underwent aK umada cross-coupling [21] in the presence of 2% Pd(OAc) 2 and 3% SPhos [22] (25 8 8C, 2h), producing biphenyl 8a in 70 %yield. Tr ansmetalation of 5a with Zn(OPiv) 2 [23] in toluene gave am ilky suspension, which reacted with 7b (25 8 8C, 15 h) in aNegishi cross-coupling in the presence of 4% of PEPPSI-i Pr, [24,25] furnishing the desired product 8b in 72 % yield (Scheme 4).…”

Cross-coupling polycondensation via C–O or C–N bond cleavage

“…On the other hand, quaternary aryl ammonium salts can be easily prepared from various anilines, and such C–N bonds exhibit higher reactivity than those of amines. Following the pioneering work by Wenkert et al in 1988 61 , applications of aryl ammonium salts for cross-coupling and related reactions have been rapidly developed in recent years by several groups 62 – 70 including ours 39 , 42 , 69 , 70 . Here, we first tried polycondensation using 1a and 5k or 5 l , with two ammonium moieties (Fig.…”