Advances in mercury(II)-salt-mediated cyclization reactions of unsaturated bonds

• Sumana Mandal,
• Raju D. Chaudhari and
• Goutam Biswas

Beilstein J. Org. Chem. 2021, 17, 2348–2376, doi:10.3762/bjoc.17.153

• diastereomers 30a,b and 32a,b was obtained, respectively. trans-Isomers were formed as major products over cis-isomers (Scheme 12) [52]. Five- and six-membered N-containing heterocyclic phosphonates were synthesized by intramolecular cyclization of alkenyl α-aminophosphonates in a similar way with the treatment

• cyclization of alkenyl α-aminophosphonates. Cyclization of 4-cycloocten-1-ol with Hg(OAc)2 forming fused bicyclic products. trans-Amino alcohol formation through Hg(II)-salt-mediated cyclization. Hg(OAc)2-mediated 2-aza- or 2-oxa-bicyclic ring formations. Hg(II)-salt-induced cyclic peroxide formation. Hg(OAc

The synthesis of α-aryl-α-aminophosphonates and α-aryl-α-aminophosphine oxides by the microwave-assisted Pudovik reaction

• Erika Bálint,
• Ádám Tajti,
• Anna Ádám,
• István Csontos,
• Konstantin Karaghiosoff,
• Mátyás Czugler,
• Péter Ábrányi-Balogh and
• György Keglevich

Beilstein J. Org. Chem. 2017, 13, 76–86, doi:10.3762/bjoc.13.10

• Economics, 1521 Budapest, Hungary Department Chemie, Ludwig-Maximilians-Universität München, 81377 München, Germany Hungarian Academy of Sciences, Research Centre for Natural Sciences, Institute of Organic Chemistry, 1519 Budapest, Hungary 10.3762/bjoc.13.10 Abstract A family of α-aryl-α-aminophosphonates

• was evaluated by DFT calculations. Two α-aminophosphonates were subjected to an X-ray study revealing a racemic dimer formation made through a N–H···O=P intermolecular hydrogen bridges pair. Keywords: α-aryl-α-aminophosphine oxides; α-aryl-α-aminophosphonates; microwave; Pudovik reaction

• ; Introduction α-Aminophosphonates and related derivatives, considered as the structural analogues of α-amino acids, have significant importance, especially in medicinal [1][2][3] and agricultural chemistry [4][5], due to their potential biological activity. The two major synthetic routes towards α

First DMAP-mediated direct conversion of Morita–Baylis–Hillman alcohols into γ-ketoallylphosphonates: Synthesis of γ-aminoallylphosphonates

• Marwa Ayadi,
• Haitham Elleuch,
• Emmanuel Vrancken and
• Farhat Rezgui

Beilstein J. Org. Chem. 2016, 12, 2906–2915, doi:10.3762/bjoc.12.290

• inhibiting them, or to have biological activities as for example antibiotics, antibacterial, anti-cancer or antithrombotic agents [22][23][24][25][26]. In this context, α-aminophosphonates have particularly attracted considerable attention owing to their biological activities [27][28][29][30][31][32][33

Enantioselective addition of diphenyl phosphonate to ketimines derived from isatins catalyzed by binaphthyl-modified organocatalysts

• Hee Seung Jang,
• Yubin Kim and
• Dae Young Kim

Beilstein J. Org. Chem. 2016, 12, 1551–1556, doi:10.3762/bjoc.12.149

• isatins has been achieved. This method affords practical and efficient access to chiral 3-amino-3-phosphonyl-substituted oxindole derivatives in high yields with excellent enantioselectivities (up to 99% ee). Keywords: 3-amino-3-phosphonyl-substituted oxindole; α-aminophosphonates; bifunctional

• organocatalyst; ketimines; organocatalysis; squaramide; Introduction α-Aminophosphonate derivatives are important compounds as structural mimics of natural α-amino acids [1][2][3]. Chiral α-aminophosphonates have been shown a wide range of biological activities including antibacterial [4] and anticancer

• properties [5], enzyme inhibition [6], peptide mimetic function [7], and herbicidal properties [8]. Since the biological activity of α-aminophosphonate derivatives is dependent upon the chirality of the α-position to the phosphorus atom, asymmetric synthesis of α-aminophosphonates has received considerable

Multicomponent reactions: A simple and efficient route to heterocyclic phosphonates

• Mohammad Haji

Beilstein J. Org. Chem. 2016, 12, 1269–1301, doi:10.3762/bjoc.12.121

• modifications The one-pot three-component reaction between aldehydes 19 (or ketones), amines 20 and dialkyl phosphonates 21 to afford α-aminophosphonates 22 is traditionally known as the Kabachnik–Fields reaction. This reaction was first reported in 1952 by Kabachnik, Medved and Fields (Scheme 6) [29][30]. Due

• to their wide range of biological activities, α-aminophosphonates have been extensively investigated and several reviews about their syntheses through the Kabachnik–Fields reaction have been reported [31][32][33]. However, an important feature of this reaction is that it provides an efficient route

• substituted isatins 30 with aniline (32) and dimethyl- or diethyl phosphite under solvent-free conditions in the presence of magnetic Fe3O4 nanoparticle-supported phosphotungstic acid as a recyclable catalyst at 80 °C furnished α-aminophosphonates 33 in yields from 80% to 98% depending on the reaction time

A new method for the synthesis of α-aminoalkylidenebisphosphonates and their asymmetric phosphonyl-phosphinyl and phosphonyl-phosphinoyl analogues

• Anna Kuźnik,
• Roman Mazurkiewicz,
• Mirosława Grymel,
• Katarzyna Zielińska,
• Jakub Adamek,
• Ewa Chmielewska,
• Marta Bochno and
• Sonia Kubica

Beilstein J. Org. Chem. 2015, 11, 1418–1424, doi:10.3762/bjoc.11.153

• Discussion Recently we developed a simple and effective two-step transformation of N-acyl-α-amino acids into their phosphonic analogues that allows for easy access to a variety of structurally diversified N-acyl-α-aminophosphonates 5 (Scheme 1) [36][37]. Despite the electron-withdrawing inductive effect of N

Synthesis and quantitative structure–activity relationship study of substituted imidazophosphor ester based tetrazolo[1,5-b]pyridazines as antinociceptive/anti-inflammatory agents

• Wafaa M. Abdou,
• Neven A. Ganoub and
• Eman Sabry

Beilstein J. Org. Chem. 2013, 9, 1730–1736, doi:10.3762/bjoc.9.199

• of our continued interest in the development of convenient synthetic approaches to β-enamino- and α-aminophosphonates with anti-inflammatory properties [13][14][15][16][17][18][19][20], we recently successfully synthesized a series of mono- and bisphosphonate-based tetrazolo[1,5-a]quinolines with

• experiments; the antinociceptive capacity was expressed as the percentage change compared to writhing controls. The results shown in Table 1 indicated that β-enaminobisphosphonate 15 is the most potent antinociceptive structure (86.4%), which was followed by α-aminophosphonates 13 (84%) and 7 (81%). Indeed

α,β-Aziridinylphosphonates by lithium amide-induced phosphonyl migration from nitrogen to carbon in terminal aziridines

• David. M. Hodgson and
• Zhaoqing Xu

Beilstein J. Org. Chem. 2010, 6, 978–983, doi:10.3762/bjoc.6.110

• group undergo cleavage at the formally benzylic C–N bond, leading to α-aminophosphonates. With β-alkyl groups, regioselectivity is influenced by the presence or absence of an N-substituent. N-Ts Cis-β-alkyl-substituted aziridinylphosphonates give β-aminophosphonates [32], whereas both N-Boc cis- and

• trans-β-alkyl-substituted aziridinylphosphonates lead to α-aminophosphonates. For example, hydrogenolysis of N-Boc trans-aziridinylphosphonate 14 (Bn instead of the C4H9 group) using 10% Pd/C (H2 (1 atm), EtOH, 12 h) has been reported to give the corresponding N-Boc α-aminophosphonate (63%) [31]. In the