Ni-Catalyzed Suzuki–Miyaura Cross-Coupling of Aliphatic Amides on the Benchtop

Abstract

Suzuki−Miyaura cross-couplings of amides offer an approach to the synthesis of ketones that avoids the use of basic or pyrophoric nucleophiles. However, these reactions require glovebox manipulations, thus limiting their practicality. We report a benchtop protocol for Suzuki− Miyaura cross-couplings of aliphatic amides that utilizes a paraffin capsule containing a Ni(0) precatalyst and NHC ligand. This methodology is broad in scope, is scalable, and provides a user-friendly approach to convert aliphatic amides to alkyl−aryl ketones.

Synthesis of meso-tetraarylthienylporphyrins by Suzuki-Miyaura cross-coupling reaction and studying their UV-Vis absorption spectra

“…Suzuki-Miyaura cross-coupling (SMC) is one of the powerful approaches to build sp 2 -sp 2 carbon-carbon bonds. 24,25 It has been used in the synthesis of many organic molecules with numerous applications in different fields. [26][27][28] The work in this study started with the search for a suitable palladium catalyst for (SMC) to prepare the 5arylthiophene-2-carboxaldehydes (Scheme 1), which are required as building blocks in the synthesis of porphyrin scaffold.…”

Ativação de Amidas – Um Instrumento Elegante para a Quimiosseletividade

“…Para ter sucesso nesta árdua tarefa, foi usado um catalisador de níquel em conjugação com ésteres borónicos, resultando numa reação de acoplamento. Mais tarde, o mesmo grupo apresentou uma solução prática para a desvantagem da sensibilidade do catalisador Ni(cod) 2 (cod = 1,5-ciclooctadieno) usando uma abordagem onde o catalisador é usado na forma de cápsulas de parafina (Esquema 2) [6]. Aplicando o catalisador estabilizado numa reação de acoplamento Suzuki-Miyaura, tendo como substrato amidas alifáticas, foi possível melhorar a versatilidade da reação [7].…”

“…Ao longo dos anos, vários grupos de investigação interessaram-se pelo problema da tensão de anel nas amidas distorcidas, com contribuições de Pracejus, Yakhontov, Brown, Blackburn, Shea, Greenberg, Williams, entre outros [8]. Apenas no final do século XIX, Kirby reportou a síntese Esquema 2 -Reação de acoplamento Suzuki-Miyaura de amidas alifáticas (pin = pinacolato) [6]. Esquema 3 -Ressonância da ligação amida.…”

Teflon Magnetic Stirring Capsules (TMSC) as a Practical and Reusable Delivery System for Sensitive Reagents and Catalysts

“…Notably, Garg and co‐workers reported benchtop protocols for a large set of Ni‐catalyzed esterifications, transamidation, Suzuki‐Miyaura and Negishi cross‐couplings. For these reactions [Ni(cod) 2 ] ( 1 ), a notoriously sensitive Ni(0) precatalyst, was wax‐encapsulated [15–17] . Other vehicles have been developed such as paraffin‐sealed glass shells or, [18] more recently, hydroxypropyl methylcellulose capsules (HPMC) [19] .…”