Synthesis of β-amino alcohols by ring opening of epoxides with amines catalyzed by cyanuric chloride under mild and solvent-free conditions

Abstract

The 2,4,6-trichloro-1,3,5-triazine catalyzed synthesis of b-amino alcohols by aminolysis of epoxide under solventfree condition is described. Mild reaction conditions, short reaction times, inexpensive and readily available catalysts, and excellent yields of the products with high regioselectivity are attractive features of this methodology.

A novel copper framework with amino tridentate N‐donor ligand as heterogeneous catalyst for ring opening of epoxides

“…Epoxides are common organic molecules with wide range of synthetic applications as intermediates in pharmaceutical and agrochemical industries. [ 1 ] The classical ring opening approach of epoxides involves heating of epoxides with large excess of amines at elevated temperature and works less well with poor nucleophilic amines, indicating that it is necessary to develop efficient catalysts for the ring opening reaction of epoxides. [ 2 ] Some homogeneous catalysts, including metal salts and acid, have already been applied.…”

A Thiophene-2-carboxamide-Functionalized Zr(IV) Organic Framework as a Prolific and Recyclable Heterogeneous Catalyst for Regioselective Ring Opening of Epoxides

“…Epoxides are considered to be privileged molecules in organic chemistry because of their versatile nucleophilic opening character, producing 1,2-difunctionalized structures, and also because such cleavages often occur with trans stereochemistry. − In the field of asymmetric catalysis, β-amino alcohols are significant as chiral ligands and chiral auxiliaries mostly originating from nature. − Amino alcohols are often derivatized to increase their chelating abilities or steric influences. , In the fields of synthetic organic chemistry, biological chemistry, and medicinal industry, β-amino alcohols have occupied a dominant position because they are used as building units for therapeutic agents, insecticidal agents, β-blockers, antimalarial agents, and numerous biologically active natural products. − Cyclic amino alcohols such as quinines are a class of naturally occurring, biologically active products that are required in the treatment of malaria . Renin and HIV-1 protein inhibitors constitute pharmacologically active amino alcohols, and one such example is saquinavir .…”

“…Often, β-adrenergic blockers, which constitute a class of β-amino alcohols, are used to regulate cardiovascular diseases such as hypertension, cardiac arrhythmias, and angina pectoris. − Ring opening of oxiranes by nucleophilic attack of various amines is the easiest way to prepare β-amino alcohols. , However, this approach is not acceptable due to its disadvantages such as the sluggish reaction rate because of the sensitivity of epoxides and decrease in regioselectivity. There are many reports involving the preparation of β-amino alcohols utilizing epoxides as electrophiles. ,− Researchers have designed several routes such as the use of homogeneous catalysts, , alumina, alkali metals, metal amides, and silica gel in order to increase the electrophilicity of epoxides. Unfortunately, most of these methods have several drawbacks such as the moisture-sensitive character of the catalysts, the low efficiency of catalysts, long reaction time, less regioselectivity, high reaction temperature and pressure, poor yield and recyclability, etc. ,,,− …”

Green Regio‐ and Enantioselective Aminolysis Catalyzed by Graphite and Graphene Oxide under Solvent‐Free Conditions

“…For styrene oxide, instead,g raphite and graphene oxide exhibited rather similar catalytic activities, and hence, the activity was mainly due to activation of the electrophilic epoxide by p-stacking interactions with the graphitic p system.T he described aminolysis procedure is green and cheap because the catalyst can be recovered and recycled without loss of efficiency.M oreover, these heterogeneous catalysts exert high stereoselective control in the presence of nonracemic epoxidesa nd provide chiral b-aminoa lcohols with enantiomeric excess values up to 99 %.Epoxider ing-opening reactions are useful methods to provide multifunctionalc ompounds ready to be used as versatile intermediates in total synthesis or as precursors of relevant molecules. As three-membered heterocyclic rings,e poxides are more reactive than ethers owing to ring strain anda re susceptible to attack by ar ange of nucleophiles, including nitrogen (e.g.,a mmonia,a mines, and azides), oxygen (e.g.,w ater,a lcohols, phenols, and acids),a nd sulfur (e.g.,t hiols) containing compounds, and this leads to bifunctional molecules of great industrial value.In particular, epoxy ring-opening reactions with amines are well documented, and with the choice of specific physical parameters (e.g.,h eating, [1,2] microwave, [3][4][5] and ultrasound [5] ), the use of polar reaction media (e.g.,i onic liquids, [6] fluoro alcohols, [7] or water under differentp Hc onditions [8,9] ), or the use of catalysts or activators as homogeneousc atalysts (e.g., Brønsteda cids and bases [6,[9][10][11][12][13][14] ands everalm etal salts and/or complexes [15][16][17][18][19][20][21][22][23][24][25][26][27][28] ), good results have been achieved, although most suffer from poor regioselectivity,h igh temperature, and/ or stoichiometrica mountso ft he catalysta nd the use of excess amounts of reagents.The use of heterog...…”

“…In particular, epoxy ring-opening reactions with amines are well documented, and with the choice of specific physical parameters (e.g.,h eating, [1,2] microwave, [3][4][5] and ultrasound [5] ), the use of polar reaction media (e.g.,i onic liquids, [6] fluoro alcohols, [7] or water under differentp Hc onditions [8,9] ), or the use of catalysts or activators as homogeneousc atalysts (e.g., Brønsteda cids and bases [6,[9][10][11][12][13][14] ands everalm etal salts and/or complexes [15][16][17][18][19][20][21][22][23][24][25][26][27][28] ), good results have been achieved, although most suffer from poor regioselectivity,h igh temperature, and/ or stoichiometrica mountso ft he catalysta nd the use of excess amounts of reagents.…”