A One-Pot Procedure for the Synthesis of α-Amino Phosphonates from Alkynes

Abstract

A new and highly flexible procedure for the synthesis of α,α-disubstituted α-amino phosphonates is described with disubstituted alkynes, primary amines and diethyl or dimethyl phosphite as starting materials. The reaction sequence, which is performed as a one-pot operation, starts with a Cp 2 TiMe 2 -catalyzed hydroamination of the alkyne. A sub-

Synthetic methods of cyclic α-aminophosphonic acids and their esters

“…After addition of diethyl phosphite together with 5 mol % Me 2 AlCl, the phosphonylated pyrrolidines 31 were obtained in good overall yields (Scheme 11). 39 Treatment of N-benzylproline (32) with oxalyl chloride followed by decarbonylation led to the formation of the iminium salt 34. 2-Phosphonopyrrolidine 25 was then obtained by addition of diethyl phosphite followed by debenzylation and dealkylation, in 90% overall yield (Scheme 12 …”

N-Benzhydrylformamide

“…-Aminophosphonic acid derivatives show activity as enzyme inhibitors, antibiotics, herbicides, fungicides or plant-growth regulators (Yang et al, 2004). Benzhydrylamine (Haak, et al, 2002), which is used as a starting material for the synthesis of -aminophosphonic acid, can be easily prepared by hydrolysis of the title compound, N-benzhydrylformamide, (I) (Leuckart & Bach, 1886), whose structure is reported here (Fig. 1).…”

Synthesis of Pyrrolidines and Pyrroles by Tandem Amination/Cyanation/Alkylation and Amination/Oxidation Sequences

“…[1] Although the synthesis of N-heterocycles has been around for over a century and a variety of well-established methods like cyclization of amine tethered C-C unsaturated system are available, [2] there are still unmet needs to carry concise and efficient synthesis of structurally more complex N-heterocycles. The need to map new chemical spaces through tandem or cascade reactions [3] in an atom economical fashion inspired us to develop a strategy to access heterocycles of different ring sizes, with different substitution patterns through cyclization triggered tandem reactions (Scheme 1). We applied this strategy successfully to tandem amination/alkynylation, [4] tandem amination/cyanation, [5] tandem amination/trifluoromethylation, [5] and tandem amination/phosphorylation sequences [6] (Scheme 1a).…”