378787-34-9Relevant academic research and scientific papers
Total synthesis of 7- and 8-oxygenated pyrano[3,2-a]carbazole and pyrano[2,3-a]carbazole alkaloids via boronic acid-catalyzed annulation of the pyran ring
Julich-Gruner, Konstanze K.,Kataeva, Olga,Schmidt, Arndt W.,Knoelker, Hans-Joachim
supporting information, p. 8536 - 8540 (2014/07/21)
The boronic acid-catalyzed annulation of citral opens up a short route to oxygenated cyclized monoterpenoid pyranocarbazole alkaloids. Thus, murrayamine-D is available in only three steps and 55% overall yield from the corresponding carbazole precursor.
Total synthesis of the biscarbazole alkaloids murrafolinea a-d by a domino sonogashira coupling/claisen rearrangement/electrocyclization reaction
Kumar, V. Pavan,Gruner, Konstanze K.,Kataeva, Olga,Knoelker, Hans-Joachim
supporting information, p. 11073 - 11077 (2013/10/22)
Why take things one step at a time? Aryl-pyran-linked biscarbazole alkaloids of the murrafoline group (see crystal structure of murrafolinea A; dark gray: C, red: O, blue: N) were accessed readily by a novel domino reaction sequence involving Sonogashira
SILANYLOXYARYL PHOSPHINE LIGAND AND USES THEREOF IN C-N CROSS-COUPLING
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Paragraph 0090-0092, (2013/11/18)
The present invention pertains to silanyloxyaryl phosphine ligands of formula (I) and their uses with transition metal catalyst precursors for organic synthesis reactions. More particularly, the present invention pertains to the use of silanyloxyaryl phosphine ligands and with transition metal catalyst precursors in C-N cross-coupling reactions.
Efficient palladium-catalyzed synthesis of substituted indoles employing a new (silanyloxyphenyl)phosphine ligand
Lavery, Christopher B.,McDonald, Robert,Stradiotto, Mark
supporting information; experimental part, p. 7277 - 7279 (2012/07/28)
The new and easily prepared OTips-DalPhos ligand (L1) offers broad substrate scope at relatively low loadings in the palladium-catalyzed C-N cross-coupling/cyclization of o-alkynylhalo(hetero)arenes with primary amines, affording indoles and related heterocyclic derivatives in high yield.
Stereoselective ring-opening polymerization of a racemic lactide by using achiral salen- and homosalen-aluminum complexes
Nomura, Nobuyoshi,Ishii, Ryohei,Yamamoto, Yoshihiko,Kondo, Tadao
, p. 4433 - 4451 (2008/02/09)
Highly isotactic polylactide or poly(lactic acid) is synthesized in a ring-opening polymerization (ROP) of racemic lactide with achiral salen- and homosalen-aluminum complexes (salenH2 = N,N′-bis(salicylidene) ethylene-1,2-diamine; homosalenH2 = N,N′-bis(salicylidene) trimethylene-1,3-diamine). A systematic exploration of ligands demonstrates the importance of the steric influence of the Schiff base moiety on the degree of isotacticity and the backbone for high activity. The complexes prepared in situ are pure enough to apply to the polymerizations without purification. The crystal structures of the key complexes are elucidated by X-ray diffraction, which confirms that they are chiral. However. analysis of the 1H and 13C NMR spec tra unambiguously demonstrates that their conformations are so flexible that the chiral environment of the complexes cannot be maintained in solution at 25°C and that the complexes are achiral under the polymerization conditions. The flexibility of the back-bone in the propagation steps is also documented. Hence, the isotacticity of the polymer occurs due to a chain-end control mechanism. The highest reactivity in the present system is obtained with the homosalen ligand with 2.2-dimethyl substituents in the backbone (ArCH=NCH2CMe2CH2N=CHAr), whereas tBuMe2Si substituents at the 3-positions of the salicylidene moieties lead to the highest selectivity (Pmeso,= 0.98; T m = 210°C). The ratio of the rate constants in the ROPs of racemic lactide and L-lactide is found to correlate with the stereoselectivity in the present system. The complex can be utilized in bulk polymerization, which is the most attractive in industry, although with some loss of stereoselectivity at high temperature, and the afforded polymer shows a higher melting temperature (Pmeso = 0.92, Tm up to 189°C) than that of homochiral poly(L-lactide) (Tm = 162-180°C). The "livingness" of the bulk polymerization at 130°C is maintained even at a high conversion (97-98%) and for an extended polymerization time (1-2 h).
