Nickel-catalyzed Suzuki–Miyaura cross-couplings of aldehydes

Abstract

Transition-metal-catalyzed cross-couplings have been extensively used in the pharmaceutical and agrochemical industries for the construction of diverse C–C bonds. Conventional cross-coupling reactions require reactive electrophilic coupling partners, such as organohalides or sulfonates, which are not environmentally friendly and not naturally abundant. Another disadvantage associated with these transformations is the need for an exogenous base to facilitate the key transmetalation step, and this reagent inevitably induces side reactions and limits the substrate scope. Here, we report an unconventional Suzuki-type approach to the synthesis of biaryls, through nickel-catalyzed deformylative cross coupling of aldehydes with organoboron reagents under base-free conditions. The transformation tolerates structurally diverse (hetero)aryl substituents on both coupling partners and shows high reactivity and excellent functional group tolerance. Furthermore, the protocol was carried out on gram scale and successfully applied to the functionalization of complex biologically active molecules. Mechanistic investigations support a catalytic cycle involving the oxidative addition of the nickel into the aldehyde C(acyl)–H bond with subsequent hydride transfer, transmetalation, decarbonylation and reductive elimination processes.

Ni/Pd-catalyzed Suzuki–Miyaura cross-coupling of alcohols and aldehydes and C–N cross-coupling of nitro and aminesviadomino redox reactions: base-free, hydride acceptor-free

“…According to the mechanism reported by Guo et al 20 for the nickel-catalyzed decarbonylative arylation reaction of aldehydes with boronic esters, and based on our observations, a general reaction mechanism was proposed for the Fe 3 O 4 @SiO 2 /(Py)copolymer-(chlorophyll b) Ni/Pd-catalyzed C-C cross-coupling reactions. Previously, alcohol oxidation to the corresponding carbonyl group could be performed using any Pd or Ni active site.…”

“…Recently, Guo et al developed an Ni-catalyzed decarbonylative arylation reaction of aldehydes with boronic esters (Scheme 2). 20 The use of the inexpensive, more accessible, and high diversity aldehydes than aryl halides was the prominent advantage of their work. Accordingly, the development of these unconventional coupling electrophiles can be a revolution in the synthesis of medicinal and biological compounds and the study and discovery of new compounds.…”

“…The aldehyde group approaches the Ni(0) centers through the C]O bond and acylates it, and the corresponding proton is taken up by the Py group (V). 20 Then, phenylboronic acid approaches to catalyst surface with the help of the Pd centers and through intermediate VI, leading to the phenyl coordination and formation of Pd(IV)-B(OH) 2 groups. The coupling product is formed aer several intermediates and the catalyst returns to the cycle by removing B(OH) 2 (CH 2 OH).…”

Hydride Transfer Enables the Nickel‐Catalyzed ipso‐Borylation and Silylation of Aldehydes

“…Based on our previous results a proposed mechanism for the above transformations is depicted in Scheme . Complex B is generated by the coordination of nickel(0) with the carbonyl moieties of the aldehyde and ketone.…”

N,N′‐bridged binuclear NHC palladium complexes: A combined experimental catalytic and computational study for the Suzuki reaction

“…[ 1 ] To date most applications have included the construction of not only carbon–carbon but also carbon–heteroatom bonds in a broad range of chemistry fields such as bioactive, conductive and fluorescent compounds, which are widely employed in pharmaceutical and materials sciences. [ 2 ] Initial cross‐coupling reactions paid more attention to the rich variety of organometallic nucleophiles that could be used for these reactions [ 3 ] and recent research interest has focused on the activation of more varied and challenging electrophiles such as aryl chlorides, [ 4 ] aryl ethers, [ 5 ] aryl esters, [ 6 ] and aldehydes, [ 7 ] or finding mild reaction conditions. [ 4a,c–f,8 ] Resulted from increasing numbers of studies gaining hands‐on experiences of developing catalysts as well as raising more insight and clear information referred to mechanistic studies have been investigated.…”