Hydrogen Autotransfer in the N-Alkylation of Amines and Related Compounds using Alcohols and Amines as Electrophiles

One pot synthesis of cyclohexanone oxime from nitrobenzene using a bifunctional catalyst

“…However, cyclohexanone 9 was not formed if 4 was reacted in the presence of the Au/C catalyst, even if Pd/C is present ( Figure 5B). Following the hydrogen-borrowing mechanism in Figure 4, it sounds plausible that cyclohexylaniline 4 could be in equilibrium with the corresponding imine 8 and, since the latter is reluctant to further amine condensation, [20][21][22] there is an opportunity for further hydrolysis to give cyclohexanone 9. To check that, the intermediate N-cyclohexylideneaniline 8 was synthesized 23 and tested under reaction conditions with the Au/C catalyst ( Figure 5C).…”

Iron catalysed direct alkylation of amines with alcohols

“…A mines are among the most valuable classes of compounds in chemistry, omnipresent in natural products, in particular alkaloids, and widely used as pharmaceuticals, agrochemicals, lubricants and surfactants [1][2][3] . Therefore the development of efficient catalytic methodologies for C-N bond formation is a paramount goal in organic chemistry 4 .…”

Microwave-Assisted Efficient Synthesis of Dialkylated Ureas from Ureas

“…Reactions with benzylic alcohols bearing an electron-donating groups, such as 4-methyl 2b, 4-isopropyl 2c and 4-methoxyl 2d, afforded the desired products 3b-3d with 68-72% yields (Table 1, entries 1-3). Similarly, benzylic alcohols bearing one or two halogen atoms, such as 4-chloro 2e, 2,4-dichloro 2f and 4-bromo 2g, were also proven to be suitable substrates, and the desired products 3e-3g were obtained with 77-80% yields (Table 1, entries [4][5][6]. The N-alkylation with benzylic alcohols bearing an electron-withdrawing trifluoromethyl 2h gave the corresponding products 3h with 73% yield (Table 1, entry 7).…”

“…Recently, much attention has been paid to the N-alkylation of amines with alcohols as environmentally benign alkylating agents instead of alkyl halides for the preparation of N-alkylated amines based on "hydrogen autotransfer" process, using iridium, ruthenium, or other transition metal catalysts. [2][3][4][5][6][7][8] In this process, alcohols are first dehydrogenated to form aldehydes with the generation of metal hydride species, then condensation between the resulting aldehydes and ketones occurs to afford imines, which undergo transfer hydrogenation to give the final N-alkylated amines. This method is apparently attractive due to the formation of water as the only side product (Scheme 1).…”