A novel straightforward synthesis of α-aminophosphonates: one-pot three-component condensation of alcohols, amines, and diethylphosphite in the presence of CuO@Fe3O4 nanoparticles as a catalyst

Highly Efficient One‐pot Aerobic Synthesis of α‐Aminophosphonate from Alcohols: Dual Catalytic Effect of Tetrabutylammonium Tribromide (TBATB)

“…withdrawing electron groups are placed on benzyl alcohol because these compounds are better oxidized according to the proposed mechanism and activity of the corresponding imines(Entries 7, 8, and 9). We found that compounds such as 4-nitrobenzyl alcohol which in some previous reports did not react due to its high activity and conversion to the corresponding acids produced 79 % of the product (Entry 7) [36] The compound of 4-methoxybenzyl alcohol did not show very good performance due to its conversion to 4-methoxybenzoic acid in the oxidation step (Entry 10). We studied benzyl alcohols and anilines including withdrawing electron groups, which showed very good results (Entries 11 and 13).…”

“…[18] In this work, we tried to consider factors such as time, solvent, catalyst amount, photo and thermal energy sources in order to achieve the one-pot synthesis of αaminophosphates. Ability of tunable aerobic oxidation benzyl alcohols to the corresponding aldehydes with high efficiency and our previous work on one-pot synthesis of α-aminophosphonate using CuO@Fe 3 O 4 magnetic nanoparticles in the group, (Scheme 1, a) [36] encouraged us to use TBATB in this one-pot reaction. The benzyl alcohol was chosen as model compound and different conditions such as solvent, amount of TBATB, time and solvent were investigated.…”

“…[18,35] According to our knowledge, to date, there are two reports on the synthesis of one-pot α-aminophosphonates from benzyl alcohols: (a) the first work was done in 2017 by Kaboudin et al In this work, first imines were prepared through aerobic oxidation of alcohol in the presence of NaOH for 4 days at toluene using CuO@Fe 3 O 4 magnetic nanoparticles. Then diethylphosphite was added to the reaction mixture to synthesize αaminophosphonates at reflux condition for 1 day [36] (b) Dangroo et al reported in 2020, benzyl alcohols were first oxidized in the presence of ammonium perchlorate under UV light irradiation and triethylphosphite and amines were added to the reaction mixture to produce α-aminophosphenates (Scheme 1) [36] In continuing of our works in the photocatalytic aerobic oxidation of alcohols and synthesis of α-aminophosphonates, here in, we report the efficient two steps one-pot synthesis of α-aminophophonates from alcohols in the presence of TBATB. [18,36]…”

“…Then diethylphosphite was added to the reaction mixture to synthesize αaminophosphonates at reflux condition for 1 day [36] (b) Dangroo et al reported in 2020, benzyl alcohols were first oxidized in the presence of ammonium perchlorate under UV light irradiation and triethylphosphite and amines were added to the reaction mixture to produce α-aminophosphenates (Scheme 1) [36] In continuing of our works in the photocatalytic aerobic oxidation of alcohols and synthesis of α-aminophosphonates, here in, we report the efficient two steps one-pot synthesis of α-aminophophonates from alcohols in the presence of TBATB. [18,36]…”

Switching the N‐Alkylation of Arylamines with Benzyl Alcohols to Imine Formation Enables the One‐Pot Synthesis of Enantioenriched α‐N‐Alkylaminophosphonates

“…To the best of our knowledge there are only two heterogeneous systems for the one‐pot condensation of anilines, alcohols and phosphites, but no homogeneous system at all. On one hand Hosseini et al reported CuO@Fe 3 O 4 nanoparticles to be suitable catalysts, on the other hand Fan and co‐workers conducted the reaction with gold supported on hydroxyapatite . With this in mind we decided to develop a homogeneous system to synthesize enantioenriched α‐aminophosphonates.…”