75834-18-3Relevant academic research and scientific papers
A General Organocatalytic System for Enantioselective Radical Conjugate Additions to Enals
Le Saux, Emilien,Ma, Dengke,Bonilla, Pablo,Holden, Catherine M.,Lustosa, Danilo,Melchiorre, Paolo
supporting information, p. 5357 - 5362 (2021/02/01)
Herein, we report a general iminium ion-based catalytic method for the enantioselective conjugate addition of carbon-centered radicals to aliphatic and aromatic enals. The process uses an organic photoredox catalyst, which absorbs blue light to generate radicals from stable precursors, in combination with a chiral amine catalyst, which secures a consistently high level of stereoselectivity. The generality of this catalytic platform is demonstrated by the stereoselective interception of a wide variety of radicals, including non-stabilized primary ones which are generally difficult to engage in asymmetric processes. The system also served to develop organocatalytic cascade reactions that combine an iminium-ion-based radical trap with an enamine-mediated step, affording stereochemically dense chiral products in one-step.
Utilizing the asymmetric amino-cope rearrangement as a novel approach to enantiomerically enriched 3-substituted aldehydes
Allin, Steven M.,Horro-Pita, Catarina,Essat, Munira,Aspinall, Ian,Shah, Pritom
experimental part, p. 2696 - 2711 (2010/11/02)
We report the asymmetric amino-Cope rearrangement of some novel 3-amino-1,5-diene substrates to yield enantiomerically enriched 3-alkyl and 3-aryl aldehyde products. We have developed a system that gives excellent and comparable levels of product enantiomeric excess (ee) for both alkyl-and aryl-substituted products. Our results have implications for the control of the mechanistic pathway of the amino-Cope rearrangement and thus its potential utility in asymmetric synthesis.
Applications of the amino-cope rearrangement: Synthesis of tetrahydropyran, δ-lactone and piperidine targets
Allin, Steven M.,Essat, Munira,Pita, Catalina Horro,Baird, Robert D.,McKee, Vickie,Elsegood, Mark,Edgar, Mark,Andrews, David M.,Shah, Pritom,Aspinall, Ian
, p. 809 - 815 (2007/10/03)
We report a novel approach to some chiral tetrahydropyran and δ-lactone targets that utilizes the asymmetric amino-Cope rearrangement as a key synthetic step. Products of amino-Cope rearrangement chemistry have also been applied to access piperidine targe
Synthetic applications of the amino-Cope rearrangement: Enantioselective synthesis of some tetrahydropyrans
Allin, Steven M.,Baird, Robert D.,Lins, Roger J.
, p. 4195 - 4197 (2007/10/03)
We report a novel and enantioselective approach to 2,4-disubstituted tetrahydropyrans that utilises the asymmetric amino-Cope rearrangement as a key synthetic step.
The first example of asymmetric induction in an anionic amino-Cope rearrangement
Allin, Steven M.,Button, Martin A. C.
, p. 3345 - 3348 (2007/10/03)
The anionic amino-Cope rearrangement of suitably functionalized acyclic 3-amino-1,5-diene substrates has been achieved and we report the first example of an asymmetric anionic amino-Cope rearrangement to yield an enantiomerically enriched product (75% e.e.). The absolute stereochemistry of the products has been verified and transition state models are proposed to rationalize the stereochemical outcome.
High asymmetric induction in anionic amino-cope rearrangements controlled by β-aminoalcohol auxiliaries
Allin, Steven M.,Button, Martin A. C.,Baird, Robert D.
, p. 1117 - 1119 (2007/10/03)
Novel 3-amino-1,5-dienes were prepared with high diastereoselectivity by unprecedented 1,2-addition of allyl Grignard to α,β-unsaturated imines containing β-aminoalcohol auxiliaries. Asymmetric anionic amino-Cope rearrangement of the diastereoisomerically pure 3-amino-1,5-diene substrates proceeded to yield the target 3-substituted aldehyde in good yield and with high levels of asymmetric induction (up to 94% e.e.).
Chiral Homoenolate Equivalents, II. - Asymmetric Synthesis of 3-Substituted 3-Phenylpropionaldehydes via Metallated Chiral Cinnamylamines
Ahlbrecht, Hubertus,Enders, Dieter,Santowski, Ludger,Zimmermann, Gerd
, p. 1995 - 2004 (2007/10/02)
The diastereomeric excess obtained in alkylation reactions of the chiral homoenolate equivalent 22 with prolinol ether as chiral auxiliary leading to the formation of phenylpropionaldehydes 24 depends strongly on the solvent used.The structure of the alkylating reagent on the other hand is not important.The best results (about 9:1) are obtained in tert-butyl methyl ether as solvent.Other chiral auxiliaries testet were uneffective. - Key Words: Chiral homoenolate equivalents / Alkylation / Chiral 1-aminoallyl anions / Chiral aldehydes
CHIRAL HOMOENOLATE EQUIVALENTS. I. ASYMMETRIC SYNTHESIS OF β-SUBSTITUTED ALDEHIDES VIA METALATED CHIRAL ALLYLAMINES
Ahlbrecht, Hubertus,Bonnet, Gerhard,Enders, Dieter,Zimmermann, Gerd
, p. 3175 - 3178 (2007/10/02)
Metalated chiral allylamines of type 2 (M = Li, K) are used as chiral homoenolate equivalents and allow after alkylation and acidic hydrolysis asymmetric C-C bond formations to β-substituted aldehydes in enantiomeric excesses up to 67percent.
