Synthesis of α-amino phosphonates
A simple, efficient, quinine-catalyzed, enantioselective hydrophosphonylation of N-Boc protected imines with diethyl poshphite gives enantiomerically enriched α-amino phosphonates in good yields.
D. Pettersen, M. Marcolini, L. Bernardi, F. Fini, R. P. Herrera, V. Sgarzani, A. Ricci, J. Org. Chem., 2006, 71, 6269-6272.
A low catalyst loading of a chiral tethered bis(8-quinolinolato) (TBOx) aluminum(III) complex effectively catalyzes the addition of phosphites to aldehydes and aldimines to give enantioenriched α-hydroxy and α-amino phosphonates in high yields and enantioselectivities.
J. P. Abell, H. Yamamoto, J. Am. Chem. Soc., 2008, 130, 10521-10523.
A chiral thiourea catalyzes the highly enantioselective hydrophosphonylation of a wide range of N-benzyl imines. Subsequent deprotection by hydrogenolysis provides access to free α-amino phosphonic acids in highly enantioenriched form.
G. D. Joly, E. N. Jacobson, J. Am. Chem. Soc., 2004, 126, 4102-4103.
A three-component coupling of amines, dihalomethane, and >P(O)H species enables a catalyst-free and selective synthesis of various phosphorus analogues of α-amino acids. This reaction takes place stereospecifically with retention of configuration at phosphorus.
Y. Zhao, X. Chen, T. Chen, Y. Zhou, S.-F. Yin, L.-B. Han, J. Org. Chem., 2015, 80, 62-69.
A general method for the reductive phosphination of amides in one pot provides α-amino phosphonates in very good yields. The reaction covers a broad scope of substrates such as secondary and tertiary amides.
Y. Gao, Z. Huang, R. Zhuang, J. Xu, P. Zhang, G. Tang, Y. Zhao, Org. Lett., 2013, 15, 4214-4217.
A simple multicomponent reaction of aldehydes, diethyl phosphite, and azides gives α-aminophosphonates in the presence of iodine and iron under solvent-free conditions. The reactions were completed at room temperature within 5 minutes to 12 hours and afforded the corresponding products in good yields.
Y.-Q. Yu, Synthesis, 2013, 45, 2545-2550.
A three-component reaction of nitro compounds, carbonyl compounds, and phosphites in the presence of indium in dilute aqueous HCl enables a high-yielding synthesis of α-amino phosphonates at room temperature. This one-pot conversion consists of reduction of nitro compounds to amines, formation of imines, and hydrophosphonylation.
B. Das, G. Satyalakshmi, K. Suneel, K. Damodar, J. Org. Chem., 2009, 74, 8400-8402.
Treatment of N-tosyl aldimines with dialkyl trimethylsilyl phosphites at 0 °C in the presence of iodine as a catalyst afforded the corresponding sulfonamide phosphonates in excellent yields in short reaction times.
B. Das, P. Balasubramanyam, M. Krishnaiah, B. Veeranjaneyulu, G. C. Reddy, J. Org. Chem., 2009, 74, 4393-4395.
A new, very mild, efficient and simple method for the preparation of tertiary α-amino phosphonates is reported. The reaction of an aldehyde, a secondary amine and trialkylphosphite in ethereal solution of lithium perchlorate (LPDE) at ambient temperature gives the desired product in high yields.
N. Azizi, M. R. Saidi, Tetrahedron, 2003, 59, 5329-5332.
A synthesis of various amino phosphonates has been achieved via phosphonate substituted carbene insertion into the N-H bond of aniline catalyzed by readily available copper salt under mild reaction conditions in water. Using this environmentally benign methodology a large number of biologically important amino phosphonates have been synthesized in good isolated yields.
K. Ramakrishna, J. M. Thomas, C. Sivasankar, J. Org. Chem., 2016, 81, 9826-9835.
A silver(I) triflate-catalyzed one-pot three-component reaction of terminal alkynes, p-anisidine, and diethyl formylphosphonate hydrate gave good yields of N-PMP protected α-aminopropargylphosphonates.
R. Dodda, C.-G. Zhao, Org. Lett., 2007, 9, 165-167.