13426-20-5Relevant academic research and scientific papers
Water-promoted dehydrative coupling of 2-aminopyridines in heptane: Via a borrowing hydrogen strategy
Azumaya, Isao,Hikawa, Hidemasa,Kikkawa, Shoko,Nakayama, Taku
, p. 23144 - 23150 (2021)
A synthetic method for dehydrative N-benzylation promoted by water molecules in heptane using a π-benzylpalladium system has been developed. The presence of water significantly accelerates carbon-nitrogen bond formation, which is accomplished in an atom-economical process to afford the corresponding N-monobenzylated products. A crossover experiment afforded H/D scrambled products, which is consistent with a borrowing hydrogen mechanism. Kinetic isotope effect measurements revealed that benzylic carbon-hydrogen bond cleavage was the rate-determining step.
A borrowing hydrogen methodology: Palladium-catalyzed dehydrative: N -benzylation of 2-aminopyridines in water
Hikawa, Hidemasa,Imamura, Hirokazu,Kikkawa, Shoko,Azumaya, Isao
supporting information, p. 3044 - 3049 (2018/07/13)
We demonstrate a greener borrowing hydrogen methodology using the π-benzylpalladium system, which offers an efficient and environmentally friendly dehydrative N-monobenzylation of 2-aminopyridines with benzylic alcohols in the absence of base. The crossover experiment using benzyl-α,α-d2 alcohol and 3-methylbenzyl alcohol afforded H/D scrambled products, suggesting that the dehydrative N-benzylation in our catalytic system involves a borrowing hydrogen pathway. KIE experiments show that C-H bond cleavage at the benzylic position of benzyl alcohol is involved in the rate-determining step (KIE = 2.9). This simple base-free protocol can be achieved under mild conditions in an atom-economic process, affording the desired products in moderate to excellent yields.
