Heck arylation of acyclic olefins employing arenediazonium salts and chiral N,N ligands: new mechanistic insights from quantum-chemical calculations

Autor(es)

Menezes da Silva, Vitor H. ^[1] ; Oliveira, Caio C. ^[1] ; Correia, Carlos Roque D. ^[1] ; Braga, Ataualpa A. C. ^[2]

Afiliação do(s) autor(es)

^[1] Univ Estadual Campinas, Inst Quim, Dept Quim Organ, CP 6154, BR-13083970 Campinas, SP - Brazil

^[2] Univ Sao Paulo, Inst Quim, Dept Quim Fundamental, Ave Prof Lineu Prestes 748, Sao Paulo, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: THEORETICAL CHEMISTRY ACCOUNTS; v. 139, n. 4 APR 4 2020.
• Citações Web of Science: 0

Resumo

A quantum-chemical study based on the Kohn-Sham density functional theory (DFT) has been performed in order to investigate the asymmetric Heck-Matsuda (HM) reactions involving a chiral N,N ligand pyrimidine-oxazoline. The oxidative addition (OA) of arenediazonium cation was analyzed to provide further insights in the unexpected high reactivity of N,N-ligated palladium(0)-based catalysts observed in these HM processes. DFT calculations suggest that the ionogenic nature of metal center promoted by the arenediazonium cation addition increases the electronic reactivity of palladium(0) toward the donor N,N ligand. The concerted and multi-step mechanisms were computed for the OA step, in which the cationic aryl-palladium(II) complex formation was revealed as the thermodynamic driving force for this process. The importance of conformational analyses was highlighted, particularly when an acyclic alkenol olefin is taken as substrate, since its absence could lead to misleading predictions about the selectivity of these HM systems. While the enantioselectivity is controlled by the combination of steric and dispersion interactions between ligand and substrate, the regioselectivity is mostly oriented by the electronic nature of olefinic carbons. DFT predictions on the selectivity were shown to be in quantitative agreement with experimental results. (AU)

• Processo FAPESP: 15/01491-3 - Estudo teórico das reações de acoplamento-cruzado: catálise homogênea e heterogênea
• Beneficiário: Ataualpa Albert Carmo Braga
• Linha de fomento: Auxílio à Pesquisa - Regular
• Processo FAPESP: 17/18207-1 - Avaliação de novos catalisadores quirais de paládio e aplicação no desenvolvimento da reação de Heck-Matsuda enantiosseletiva em novos modelos olefínicos: estudos computacionais
• Beneficiário: Vitor Hugo Menezes da Silva
• Linha de fomento: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 14/25770-6 - Novas fronteiras em reações de acoplamento cruzado mediadas por paládio: associando catálise enantiosseletiva, ativações C-H, novos materiais e reações em fluxo visando alta eficiência e sustentabilidade em processos sintéticos
• Beneficiário: Carlos Roque Duarte Correia
• Linha de fomento: Auxílio à Pesquisa - Temático