3423-13-0Relevant academic research and scientific papers
Unexpected unique behavior of spiro-isoquinolines with a cyclohexadienone system in attempted dienone-phenol rearrangement
Shigehisa, Hiroki,Honda, Toshio
, p. 1233 - 1239 (2008)
8',9'-Dimethoxy-1',5',6',10b'-tetrahydro-4H-spiro(cyclohexa-2,5-diene-1,2'-pyrrolo[2,1-a]isoquinoline)-3',4-dione 2 with a basic skeleton of a natural product, annnosqualine, exhibited unique behavior in a dienone-phenol rearrangement. Treatment of 2 with trifluoroacetic acid gave a simple 1-benzylisoquinoline alkaloid, norarmepavine 4. Plausible reaction mechanism for the observed transformation is also described.
Synthesis of new dopamine D1 antagonist SCH 23390 analogues by the stereoselective stevens rearrangement
Ariza, Manuela,Diaz, Amelia,Suau, Rafael,Valpuesta, Maria
, p. 6507 - 6518 (2011)
A convenient synthesis for new SCH 23390 analogues bearing different substituents at the C-1 position has been developed by using the diastereoselective Stevens rearrangement. This procedure has provided a good number of new 1,2-disubstituted 1H-3-benzaze
Light-Induced Alkylation of (Hetero)aromatic Nitriles in a Transition-Metal-Free C-C-Bond Metathesis
Lipp, Benjamin,Lipp, Alexander,Detert, Heiner,Opatz, Till
supporting information, p. 2054 - 2057 (2017/04/27)
A light-induced C-C-σ-bond metathesis was achieved through transition-metal-free activation of an unstrained C(sp3)-C(sp3)-σ-bond in 1-benzyl-1,2,3,4-tetrahydroisoquinolines. A photoredox-mediated single-electron oxidation of these precursor amines yield radical cations which undergo a homolytic cleavage of a C(sp3)-C(sp3)-σ-bond rather than the well-known α-C-H-scission. The resulting carbon-centered radicals are used in the ipso-substitution of (hetero)aromatic nitriles proceeding through another single-electron transfer-mediated C-C-bond cleavage and formation.
Deracemization by simultaneous bio-oxidative kinetic resolution and stereoinversion
Schrittwieser, Joerg H.,Groenendaal, Bas,Resch, Verena,Ghislieri, Diego,Wallner, Silvia,Fischereder, Eva-Maria,Fuchs, Elisabeth,Grischek, Barbara,Sattler, Johann H.,MacHeroux, Peter,Turner, Nicholas J.,Kroutil, Wolfgang
supporting information, p. 3731 - 3734 (2014/04/17)
Deracemization, that is, the transformation of a racemate into a single product enantiomer with theoretically 100-% conversion and 100-% ee, is an appealing but also challenging option for asymmetric synthesis. Herein a novel chemo-enzymatic deracemization concept by a cascade is described: the pathway involves two enantioselective oxidation steps and one non-stereoselective reduction step, enabling stereoinversion and a simultaneous kinetic resolution. The concept was exemplified for the transformation of rac-benzylisoquinolines to optically pure (S)-berbines. The racemic substrates were transformed to optically pure products (ee>97-%) with up to 98-% conversion and up to 88-% yield of isolated product. From two make one: Chemo-enzymatic stereoinversion and enzymatic kinetic resolution have been combined in a simultaneous cascade process to transform racemic substrates (A, ent-A) into optically pure product P. The concept was exemplified for benzylisoquinolines rac-1 yielding optically pure berbines (S)-2. The reaction system comprised a monoamine oxidase (MAO-N), morpholine-borane, and the berberine bridge enzyme (BBE).
Synthesis and biological evaluation of N-methyl-laudanosine iodide analogues as potential SK channel blockers
Graulich,Mercier,Scuvee-Moreau,Seutin,Liegeois
, p. 1201 - 1209 (2007/10/03)
Neuronal action potentials are followed by an afterhyperpolarisation (AHP), which is mediated by small conductance Ca2+-activated K+ channels (SK channels or KCa2 channels). This AHP plays an important role in regulating neuronal act
A convenient synthesis of 1-benzyl-1,2,3,4-tetrahydroisoquinolines by combined Strecker/Bruylants reaction
Reimann, Eberhard,Ettmayr, Christian
, p. 1289 - 1295 (2007/10/03)
Strecker reaction of iodophenethylamines with phenylacetaldehydes afforded the corresponding α-aminonitriles, which on treatment with i-propyl magnesium chloride underwent a Bruylants reaction to give the title compounds. Their structures were deduced by NMR and by an independent preparation starting from papaverine. The educts were easily available by standard procedures. Springer-Verlag 2004.
Novel Zinc-Promoted Alkylation of Iminium Salts. New Synthesis of Benzylisoquinoline, Phthalidylisoquinoline, and Protoberberine Alkaloids and Related Compounds
Shono, Tatsuya,Hamaguchi, Hiroshi,Sasaki, Manji,Fujita, Shumei,Nagami, Kimihiko
, p. 1621 - 1628 (2007/10/02)
Zinc-promoted reductive coupling reaction of iminium salts with alkyl halides was found to be a successful key reaction for synthesis of a variety of alkaloids such as benzylisoquinoline, phthalidylisoquinoline, and protoberberine alkaloids.More specifically, laudanosine, cordrastine, hydrastine, narcotine, tetrahydropalmatine, and canadine were obtained.A new route for the synthesis of the emetine and yohimbine skeletons was exploited.
