Synthesis of β-amino alcohols
Zinc(II) perchlorate hexahydrate is a highly efficient catalyst for the opening of epoxides by amines affording 2-amino alcohols in high yields under solvent-free conditions and with excellent chemo-, regio-, and stereoselectivities.
Shivani, B. Pujala, A. K. Chakraborti, J. Org. Chem., 2007, 72, 3713-3722.
The mild aminolysis of a variety of epoxides in water gave β-amino alcohols with high selectivity and in excellent yields in the absence of any catalyst.
N. Azizi, M. R. Saidi, Org. Lett., 2005, 7, 3649-3651.
A variety of polar mixed solvent systems enable an efficient and regioselective synthesis of β-amino alcohols from a variety of epoxides and primary amines in high yields in the absence of any catalyst.
J. R. Lizza, G. Moura-Letts, Synthesis, 2017, 49, 1231-1242.
Highly regioselective ring opening of epoxides with poor nucleophiles such as indole, borane, O-trimethylsilylhydroxylamine, p-nitroaniline and sterically hindered tert-butylamine is a fast and convenient reaction in the presence of 5.0 M lithium perchlorate-Et2O solution (LPDE).
A. Heydari, M. Mehrdad, A. Maleki, N. Ahmadi, Synthesis, 2004, 1557-1558.
Sc(OSO3C12H25)3 catalyses the asymmetric ring opening of meso-epoxides with aromatic amines in the presence of 1.2 mol-% of a chiral bipyridine ligand to afford β-amino alcohols in high yields with excellent enantioselectivities using water as environmentally benign solvent.
S. Azoulay, K. Manabe, S. Kobayashi, Org. Lett., 2005, 7, 4593-4595.
A readily synthesized chiral sulfinamide based organocatalyst enables an asymmetric ring-opening (ARO) reaction of meso epoxides with anilines in high yields of with excellent enantioselectivity at room temperature. A probable mechanism for the catalytic ARO reaction is envisaged by 1H and 13C NMR experiments.
M. Kumar, R. I. Kureshy, S. Saravanan, S. Verma, A. Jakhar, N.-u. H. Khan, S. H. R. Abdi, H. C. Bajaj, Org. Lett., 2014, 16, 2798-2801.
A mild, calcium trifluoromethanesulfonate-catalyzed aminolysis of epoxides is very efficient in the synthesis of various β-amino alcohols with high regio- and stereoselectivity.
I. Cepanec, M. Litvic, H. Mikuldas, A. Bartolincic, V. Vinkovic, Tetrahedron, 2003, 59, 2435-2439.
Silica gel (60–120 mesh) efficiently catalyses the opening of epoxides by amines at r.t. under solvent-free conditions. Non-styrenoidal unsymmetrical alkene oxides undergo selective nucleophilic attack at the sterically less hindered carbon by aniline. A complementary regioselectivity is exhibited by aromatic and aliphatic amines during the reaction with styrene oxide.
A. K. Chakraborti, S. Rudrawar, A. Kondaskar, Org. Biomol. Chem., 2004, 2, 1277-1280.
In a radical-mediated strategy for β C-H amination of alcohols, imidates as radical relay chaperones serve as traceless directors that facilitates selective C-H functionalization via 1,5-hydrogen atom transfer (HAT) and enable net incorporation of ammonia at the β carbon. A streamlined protocol enables rapid conversion of alcohols to their β-amino analogs (via in situ conversion of alcohols to imidates, directed C-H amination, and hydrolysis).
E. A. Wappes, K. M. Nakafuku, D. A. Nagib, J. Am. Chem. Soc., 2017, 139, 10204-10207.
An efficient, directed reductive amination of β-hydroxy-ketones allows the stereoselective preparation of 1,3-syn-amino alcohols using Ti(iOPr)4 for coordination of the intermediate imino alcohol and PMHS as the reducing agent.
D. Menche, F. Arikan, J. Li, S. Rudolph, Org. Lett., 2007, 9, 267-270.
Biologically important N-β-hydroxyethylaziridine intermediates were conveniently prepared by regioselective ring-opening reactions of various epoxides with in situ-generated ethyleneimine from β-chloroethylamine under basic conditions in an aqueous environment.
H. Y. Kim, A. Talukdar, M. Cushman, Org. Lett., 2006, 8, 1085-1087.
A simple, efficient, and environmentally benign methodology allows the synthesis of β-amino alcohols from aromatic amines and alkylene carbonates in the presence of the highly active and reusable solid base catalyst Na-Y zeolite.
A. B. Shivarkar, S. P. Gupte, R. V. Chaudhari, Synlett, 2006, 1374-1378.
Photoredox-catalyzed and nitrogen-centered radical-triggered cascade reactions of styrenes (or phenylacetylenes), enol derivatives, and O-acyl hydroxylamines in DMSO provide functionalized β-amino alcohols. Structurally diverse reaction components, including complex molecular scaffolds can be converted.
X.-D. An, Y.-Y. Jiao, H. Zhang, Y. Gao, S. Yu, Org. Lett., 2018, 20, 401-404.
A catalytic, highly C3-selective, stereosepecific ring-opening reaction of 2,3-epoxy alcohols and 2,3-epoxy sulfonamides is efficiently promoted by W-salts. The developed method was applicable to various epoxides with diverse N- and O-nucleophiles affording the products in good to excellent yields (up to 95%) and generally with high regioselectivities (C3:C2 up to >99:1).
C. Wang, H. Yamamoto, J. Am. Chem. Soc., 2014, 136, 6888-6891.
An intermolecular Pd-catalyzed aminoacetoxylation of alkenes with phthalimide as the nitrogen source and PhI(OAc)2 as the stoichiometric oxidant and source of acetate achieves a highly regio- and diastereoselective oxidative 1,2-difunctionalization of alkenes. The mechanism is discussed.
G. Liu, S. S. Stahl, J. Am. Chem. Soc., 2006, 128, 7179-7181.
A highly regio- and enantioselective hydroxyamination of aldehydes with in situ generated nitrosocarbonyl compounds from hydroxamic acid derivatives was realized by combining TEMPO and BPO as oxidants in the presence of a binaphthyl-modified amine catalyst.
T. Kano, F. Shirozu, K. Maruoka, J. Am. Chem. Soc., 2013, 135, 17735-17738.
A palladium-catalyzed allylic amination enables an asymmetric synthesis of α,α-disubstituted allylic N-arylamines from highly modular vinyl cyclic carbonates and unactivated aromatic amine nucleophiles. The catalytic process features minimal waste production, high asymmetric induction, and operational simplicity.
A. Cai, W. Guo, L. Martínez-Rodríguez, A. W. Kleij, J. Am. Chem. Soc., 2016, 138, 14194-14197.