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Search for "enamines" in Full Text gives 86 result(s) in Beilstein Journal of Organic Chemistry.
An intramolecular inverse electron demand Diels–Alder approach to annulated α-carbolines
Beilstein J. Org. Chem. 2012, 8, 829–840, doi:10.3762/bjoc.8.93
- triazines (9, R1 = NO2, CONH2), but due to the electron withdrawing nature of the isatin substituents, subsequent sulfonylations were not successful (not shown). The intermolecular IEDDA reactions of 8a with various electron-rich dienophiles, including ethyl ethynyl ether, the enamines (E)-1-N
Chemistry of polyhalogenated nitrobutadienes, 10: Synthesis of highly functionalized heterocycles with a rigid 6-amino-3-azabicyclo[3.1.0]hexane moiety
Beilstein J. Org. Chem. 2012, 8, 621–628, doi:10.3762/bjoc.8.69
- chlorides result in the formation of the enamines 11, 12, 13, 16, 25, the amidine 6, and the amides 20, 21, respectively. In the following, cyclization to the highly functionalized pyrazoles 27, 28, pyrimidine 26 and pyridopyrimidine 24 succeeded. Deprotection of 21, 12 and 28 proved to be only partially
Stereoselective, nitro-Mannich/lactamisation cascades for the direct synthesis of heavily decorated 5-nitropiperidin-2-ones and related heterocycles
Beilstein J. Org. Chem. 2012, 8, 567–578, doi:10.3762/bjoc.8.64
- ][28][29], reduction of unsaturated heterocycles [30][31][32], ring closure via intramolecular nucleophilic substitution [33][34][35][36][37], cascade reactions of enamines/imines and aldehydes [38][39][40][41], and ring-closing metathesis followed by hydrogenation [42][43][44][45][46][47][48
Combination of gold catalysis and Selectfluor for the synthesis of fluorinated nitrogen heterocycles
Beilstein J. Org. Chem. 2011, 7, 1379–1386, doi:10.3762/bjoc.7.162
- %, respectively. In the absence of a gold catalyst, a similar result was obtained (Scheme 5) confirming that Selectfluor itself can react with 6 and 7 to give 3a and 5a, which is consistent with Shreeve’s study on the fluorination of enamines [29]. However, the formation of 5a may also be ascribed to the
- could be explained as outlined in Scheme 6. The cationic Au(I) catalyst would promote the cyclization of 1a to the mixture of enamines 6 and 7 as previously observed with cationic Au(III) species (Scheme 4). Activation of the electron rich double bond of 6 or 7 by the cationic Au(I) complex could
- ), 39.2 (CH2), 27.7 (CH2), 26.6 (CH3), 22.7 (CH2), 21.7 (CH3), 21.6 (CH3); IR (neat) 1452, 1332, 1154, 1089, 1000, 811, 655 cm−1; HRMS (m/z): [M + Na]+ calcd for C24H30N2O4S2, 497.1539; found, 497.1517. Synthesis of cyclic enamines Cyclic enamines were synthesized in 59% yield (endo/exo 2:3) according to
Selectivity in C-alkylation of dianions of protected 6-methyluridine
Beilstein J. Org. Chem. 2011, 7, 1228–1233, doi:10.3762/bjoc.7.143
- substituted by one nitrogen at the central carbon (C=C(N)–C) has scarcely been studied [38][39][40]. Deprotonation of simple enamines or allylamines employing n-BuLi and t-BuLi/t-BuOK produced nitrogen-substituted allylic anions which undergo protonation, alkylation, trimethylsilylation and reaction with
Multicomponent reaction access to complex quinolines via oxidation of the Povarov adducts
Beilstein J. Org. Chem. 2011, 7, 980–987, doi:10.3762/bjoc.7.110
- through the Povarov MCR (the interaction of anilines, aldehydes and activated olefin inputs under acid catalysis) [4][5][6][7][8]. Interestingly, this process allows cyclic enol ethers and enamines to be used as electron-rich alkenes, leading to heterocycle-fused tetrahydroquinolines, usually as a mixture
Palladium- and copper-mediated N-aryl bond formation reactions for the synthesis of biological active compounds
Beilstein J. Org. Chem. 2011, 7, 59–74, doi:10.3762/bjoc.7.10
- , carbamates, N-heterocycles, enamines and intramolecular N-arylation reactions [45]. We compare here the success of the different C–N-arylation reactions as applied to the synthesis of more complex structures and discuss selected examples of palladium- and copper-mediated reactions for the synthesis of
Development of dynamic kinetic resolution on large scale for (±)-1-phenylethylamine
Beilstein J. Org. Chem. 2010, 6, 823–829, doi:10.3762/bjoc.6.97
- for their preparation that are applicable on multigram scale. They can be prepared by resolution of amines, hydrogenation of prochiral imines and enamines [1][2], alkylation of prochiral imines [3], aminohydroxylation of alkenes [4], transamination of prochiral ketones [5][6][7], and reductive
Shelf-stable electrophilic trifluoromethylating reagents: A brief historical perspective
Beilstein J. Org. Chem. 2010, 6, No. 65, doi:10.3762/bjoc.6.65
- , enamines, and thiolate anions with these reagents, albeit in low to moderate yields [28]. Neutral hypervalent iodine(III)–CF3 reagent Initial attempts by Yagupolskii and Umemoto to synthesize iodonium salts with a trifluoromethyl group were unsuccessful. Whilst iodonium salts including p
Diastereoselective functionalisation of benzo-annulated bicyclic sultams: Application for the synthesis of cis-2,4-diarylpyrrolidines
Beilstein J. Org. Chem. 2009, 5, No. 69, doi:10.3762/bjoc.5.69
- ). Functionalisation of the N-sulfonyl enamines 5a and 5b was subsequently studied with the ultimate aim of introducing substituents, in a stereoselective fashion, to the masked pyrrolidine ring. Thus, epoxidation of 5a and 5b (Scheme 3) using m-CPBA proceeded smoothly for both substrates and as hoped, occurred under
Total synthesis of the indolizidine alkaloid tashiromine
Beilstein J. Org. Chem. 2008, 4, No. 8, doi:10.1186/1860-5397-4-8
- structure, including radical cyclisations [3]; nucleophilic addition to imines [5][14][15]; electrophilic alkylation of pyrroles [7][13]; alkylation of enamines [6], β-amino esters [8] and pyrrolidinyllithiums [12]; stereoselective reduction of enamines [4][9] and pyridinium salts [11]; and titanium
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