131489-59-3Relevant academic research and scientific papers
Synthesis of Boronic Ester γ-Lactam Building Blocks
Rodgers, George,Wilson, Ellen J.,Robertson, Craig C.,Cox, Daniel J.,Partridge, Benjamin M.
, p. 2392 - 2395 (2021)
Saturated heterocycles are found widely in biologically active compounds such as medicinal drugs and agrochemicals. However, boronic acid-derived building blocks for these structures have limited availability, particularly in comparison to heteroaromatic boronic acids. We report the preparation of boronic ester γ-lactams through a Cu-catalysed conjugate borylation-cyclisation protocol. Using a chiral catalyst, this can be performed in high enantioselectivity. Exploration of the further transformations of these reagents suggest that the boronic esters have much potential as chemical building blocks. (Figure presented.).
Enantioselective phase-transfer-catalyzed intramolecular Aza-Michael reaction: Effective route to pyrazino-indole compounds
Bandini, Marco,Eichholzer, Astrid,Tragni, Michele,Umani-Ronchi, Achille
, p. 3238 - 3241 (2008/12/23)
(Chemical Equation Presented) Producing polycycles: A mild and direct stereocontrolled route to pharmacologically active pyrazino-indol-1-ones has been developed. The optimal phase-transfer conditions provide variously functionalized ring-closed compounds
Cyclic β-amino acid derivatives: Synthesis via lithium amide promoted tandem asymmetric conjugate addition-cyclisation reactions
Davies, Stephen G.,Diez, David,Dominguez, Sara H.,Garrido, Narciso M.,Kruchinin, Dennis,Price, Paul D.,Smith, Andrew D.
, p. 1284 - 1301 (2007/10/03)
The product distribution upon conjugate addition of homochiral lithium N-benzyl-N-α-methylbenzylamide to dimethyl-(E,E)-nona-2,7-dienedioate can be controlled to give either the cyclic 1,2-anti-1,6-anti-β-amino ester (derived from conjugate addition and i
Pyrimidine annelated heterocycles-synthesis and cycloaddition of the first pyrimido[1,4]diazepine N-oxides
Heaney, Frances,Burke, Cathriona,Cunningham, Desmond,McArdle, Patrick
, p. 622 - 632 (2007/10/03)
5-Formyl- and 5-acetyl-4-(alkenylamino)pyrimidines 5 have been prepared as precursors to novel pyrimido[1,4]-diazepine N-oxides 3. In addition to cyclisation to the targeted dipoles the substrates 5 have also been observed to form imidazopyrimidines 12 and 39 via an intramolecular Michael addition; additionally 5b has been observed to form the pyrimidoazepinone 42. Aldonitrone 3a cycloadded readily to olefinic dipolarophiles; ketodipole 3b did not share this reactivity. Both dipoles reacted with acetylenic dipolarophiles but the ensuing cycloadducts 37 were unstable; facile ring contraction of their isoxazolopyrimidodiazepine skeletons to the pteridine nucleus is noted. The structure of 37c has been determined by X-ray crystallography.
Amination of(η3-allyl)dicarbonylnitrosyliron complexes: A route to γ- amino-α,β-unsaturated carboxylic acid derivatives
Nakanishi, Saburo,Okamoto, Kenji,Yamaguchi, Hiroshi,Takata, Toshikazu
, p. 1735 - 1741 (2007/10/03)
Amines reacted regioselectively with (ν3-allyl)dicarbonylnitrosyliron complexes having ester group on the allyl ligand to give γ-amino-α,β- unsaturated esters in high yields. A remarkable effect of the substituents attached to the allyl ligand was observed on the reaction rate and regioselectivity of the amination. The methoxycarbonyl group significantly accelerates the reaction rate and enhances the regioselectivity of the reaction. The phenyl group retards the reaction, but enhances the regioselectivity, while alkyl groups retard the reaction and diminish the regioselectivity.
Preparation of imidazo[1,2-c]pyrimidinones from a chloropyrimidine and an electron poor ω-allylic amine
Heaney, Frances,Bourke, Sharon,Burke, Cathriona,Cunningham, Desmond,McArdle, Patrick
, p. 2255 - 2257 (2007/10/03)
Synthesis of the title ring system by a sequential intermolecular nucleophilic displacement and intramolecular 'conjugate' addition has been achieved both as a one pot and as a stepwise procedure; an X-ray structure determination has been carried out to distinguish between the possible isomeric structures 8c-I and 8c-II.
Nucleophilic displacement reactions of 4-(nosyloxy)-2,3-unsaturated esters and 2-(nosyloxy)-3,4-unsaturated esters
Hoffman, Robert V.,Severns, Bryon S.
, p. 5567 - 5573 (2007/10/03)
It has been found that 4-(nosyloxy)-2,3-unsaturated esters 2 undergo direct displacement with a wide variety of nucleophiles and yield 4-substituted-2,3-unsaturated products cleanly and in generally good yields. These materials thus have very good synthetic potential for the formation of densely functionalized unsaturated esters. 2-(Nosyloxy)-3,4-unsaturated esters as exemplified by methyl 2-(nosyloxy)-3-butenoate (3d) also undergo direct displacement with a range of good nucleophiles; however, the resulting substitution products are prone to rearrangements and tautomerism, as is the starting material itself, so that the synthetic utility of these compounds is limited.
Regiochemical Control in the Preparation of 2-(Nosyloxy) β,γ-Unsaturated Esters and 4-(Nosyloxy) α,β-Unsaturated Esters from 1--1-alkoxy 1,3-Dienes
Hoffman, Robert V.,Kim, Hwa-Ok
, p. 1014 - 1019 (2007/10/02)
A series of 1--1-alkoxy 1,3-dienes 1a-i were found to react with p-nitrobenzenesulfonyl peroxide in the presence of sodium methoxide or zinc chloride to give alkyl 2 -oxy> β,γ-unsaturated esters 3 and 4-(p-n
