Organoaluminum‐Mediated Direct Cross‐Coupling Reactions

Abstract

We present a direct cross-coupling reaction between arylaluminum compounds (ArAlMe2 ⋅LiCl) and organic halides RX (R=aryl, alkenyl, alkynyl; X=I, Br, and Cl) without any external catalyst. The reaction takes place smoothly, simply upon heating, thereby enabling the efficient and chemo-/stereoselective formation of biaryl, alkene, and alkyne coupling products with broad functional group compatibility.

Comparing Neutral (Monometallic) and Anionic (Bimetallic) Aluminum Complexes in Hydroboration Catalysis: Influences of Lithium Cooperation and Ligand Set

“…[3] For example, they are utilised in CÀC cross coupling chemistries, and in deprotonative metalation. [4] Catalytic hydroelementation reactions have also witnessed impressive progress in the past few years. Roesky and coworkers demonstrated that a b-diketiminato stabilised aluminium hydride complex is an excellent catalyst for hydroboration of alkynes and carbonyl groups.…”

Transition‐Metal‐Free Reaction of Aryltrimethylammonium Iodides with Arylzinc Reagents

“…Uchiyama et al. carried out direct reaction between arylaluminum compounds and organic halides . Ingleson described transition‐metal‐free reaction of diaryl zinc reagents with alkyl halides .…”

“…On the other hand, transition‐metal‐free reactions are attracting more and more attention because they are less costly and more environmentally friendly and can avoid any transition metal impurities in pharmaceutical products . For example, Hayashi et al.…”

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

“…Consequently, TM‐free cross‐coupling methods have attracted much attention in recent years . Some elegant direct cross‐coupling reactions between organometallics (R–M) and organohalides (R–Hal) have been developed, in which R–M (such as Mg, Zn, Al, and Sn,) reacts efficiently with various types of organohalides, including R–I, R—Br, and even unreactive R–Cl (Scheme a). The mechanisms of these direct cross‐coupling reactions have been clarified by means of both experimental–– and theoretical methods.…”