875535-33-4Relevant academic research and scientific papers
Direct Catalytic Asymmetric Addition of Acetonitrile to Aldimines
Saito, Akira,Kumagai, Naoya,Shibasaki, Masakatsu
, p. 8187 - 8190 (2019/09/07)
Despite significant advances in catalytic asymmetric reactions with decent stereocontrol, those using acetonitrile as a pronucleophile are often disregarded due to their low reactivity and insufficient enantioselectivity. Herein we report the resurgence of this reaction in the chemical toolbox with high enantioselectivity (avg. > 95% ee). The combined use of a Ni(II) complex ligated with a chiral biscarbene and tBuOK engages acetonitrile in the catalytic generation of an α-cyanocarbanion and subsequent highly enantioselective addition to aldimines.
Metal-free one-pot synthesis of 2-substituted and 2,3-disubstituted morpholines from aziridines
Sun, Hongnan,Huang, Binbin,Lin, Run,Yang, Chao,Xia, Wujiong
, p. 524 - 529 (2015/06/08)
The metal-free synthesis of 2-substituted and 2,3-disubstituted morpholines through a one-pot strategy is described. A simple and inexpensive ammonium persulfate salt enables the reaction of aziridines with halogenated alcohols to proceed via an SN2-type ring opening followed by cyclization of the resulting haloalkoxy amine.
Catalytic enantioselective reaction of α-phenylthioacetonitriles with imines using chiral bis(imidazoline)-palladium catalysts
Kondo, Masaru,Kobayashi, Natsumi,Hatanaka, Tsubasa,Funahashi, Yasuhiro,Nakamura, Shuichi
, p. 9066 - 9070 (2015/06/16)
The catalytic enantioselective reaction of α-phenylthioacetonitriles with imines has been developed. The reaction of various imines proceeds in good yields and diastereo- and enantioselectivities in the presence of chiral bis(imidazoline)-palladium cataly
Catalytic enantioselective decarboxylative cyanoalkylation of imines by using palladium pincer complexes with C2-symmetric chiral Bis(imidazoline)s
Hyodo, Kengo,Kondo, Masaru,Funahashi, Yasuhiro,Nakamura, Shuichi
supporting information, p. 4128 - 4134 (2013/05/09)
Manifold products: The enantioselective decarboxylative Mannich-type reaction of cyanoacetic acid with N- (2-pyridinesulfonyl)imines catalyzed by chiral 1,3-bis(imidazolin-2-yl)benzene (Phebim)-PdII complexes afforded products with good enantioselectivity (see scheme). The reaction was applied to a wide range of imines with good yield and enantioselectivity. The obtained products can be converted into various compounds without the loss of enantiopurity. Copyright
Stereoselective synthesis of 2,4,5-trisubstituted piperidines via radical cyclization
Ragoussi, Maria-Eleni,Walker, Stephen M.,Piccanello, Andrea,Kariuki, Benson M.,Horton, Peter N.,Spencer, Neil,Snaith, John S.
, p. 7347 - 7357 (2011/02/16)
A novel approach to 2,4,5-trisubstituted piperidines is reported, involving the 6-exo cyclization of stabilized radicals onto α,β-unsaturated esters. Only two of the four possible diastereoisomers are observed, with diastereomeric ratios ranging from 3:2
Stereoselective synthesis of 2,4,5-trisubstituted piperidines by carbonyl ene and Prins cyclisations
Cariou, Claire A.M.,Kariuki, Benson M.,Snaith, John S.
supporting information; experimental part, p. 3337 - 3348 (2009/02/05)
An approach to 2,4,5-trisubstituted piperidines is reported, in which the key step is the Prins or carbonyl ene cyclisation of aldehydes of the type 1. Prins cyclisation catalysed by concentrated hydrochloric acid in CH 2Cl2 at -78 °C afforded good yields of two of the four possible diastereomeric piperidines, with the 4,5-cis product 7 predominating in a diastereomeric ratio of up to 94: 6. The diastereoselectivity of the cyclisation decreased as the 2-substituent increased in size, becoming unselective for very bulky 2-substituents. In contrast, cyclisation catalysed by MeAlCl2 in CH2Cl2 or CHCl3 at temperatures of between 20-60 °C, favoured the 4,5-trans diastereomer 8, in a diastereomeric ratio of up to 99: 1. The low-temperature cyclisations catalysed by HCl proceed under kinetic control via a mechanism involving the development of significant carbocationic character, in which the 4,5-cis cation is more stable than the 4,5-trans cation as a result of overlap with the neighbouring oxygen. The cyclisations catalysed by MeAlCl2 proceed under thermodynamic control, affording the product in which both the 4- and 5-substituents are equatorial.
Stereoselective synthesis of 2,4,5-trisubstituted piperidines by carbonyl ene and Prins cyclisations
Cariou, Claire A. M.,Snaith, John S.
, p. 51 - 53 (2007/10/03)
Intramolecular carbonyl ene reactions present a method for ring closure, leading to the formation of two contiguous stereocentres with an often high degree of stereocontrol. The extension of this approach to the synthesis of 2,4,5-trisubstituted piperidin
