نتایج جستجو برای: friedländer hetero annulation
تعداد نتایج: 5992 فیلتر نتایج به سال:
We describe a straightforward protocol for a smooth dehydrogenative annulation reaction between various arenes and terminal alkynes using a catalytic amount of CuBr2 and molecular oxygen. 3-Methyleneisoindoline derivatives are prepared in high yields.
Hypervalent iodine(III)-induced oxidative [4+2] annulation of o-phenylenediamines and electron-deficient alkynes under metal-free conditions has been developed. The reaction allows for direct access to quinoxalines bearing two electron-withdrawing groups in an efficient manner.
The chiral N-heterocyclic carbene-catalyzed [3 + 2] annulation of α-bromoenals and 3-aminooxindoles was developed, giving the corresponding spirocyclic oxindolo-γ-lactams in good yields with high diastereoselectivities and enantioselectivities.
Tandem rhodium-catalyzed oxidative allylation and annulation of acetanilides with allyl acetate to afford the corresponding indoles are described. In addition, the site-selective C2 allylation, crotylation and prenylation of indoles using allylic acetates under rhodium catalysis are reported.
Recent advances in chiral-phosphine-catalyzed asymmetric annulation reactions; including annulations of allenes, alkynes, Morita-Baylis-Hillman (MBH) carbonates, and ketenes; and their applications in the synthesis of bioactive molecules and natural products are reviewed.
When Boc-L-Val-OH was used as a ligand for the enantioselective Pd(II)-catalyzed annulation of N,N-substituted aminomethyl ferrocene derivatives with diarylethynes, ferrocenes with planar chirality could be achieved with excellent enantioselectivity (up to 99% ee).
1. The meningococcus polysaccharide reacts with a broad precipitable carbohydrate antibody in common with those of B. anthracis, B. subtilis, B. proteus and B. mesentericus. 2. The anthrax and proteus polysaccharides are specific in the higher dilutions of serum. 3. Antianthrax serum contains two different polysaccharide precipitable antibodies, one specific and the other non-specific. 4. Agglu...
A facile and inexpensive synthesis of a series of novel methylenedioxy-bearing 2-(benzofuran-2-yl)-quinoline-3-carboxylic acid derivatives 3a-h via the one-pot reaction of ethyl 2-chloromethyl-6,7-methylenedioxyquinoline-3-carboxylate (5) with various substituted salicylaldehydes 6a-g as well as 2-hydroxy-1-naphthaldehyde (6h) is described. Substrate 5 was synthesized by the Friedländer condens...
Abstract Bicyclic alkenes, including oxa- and azabicyclic readily undergo activation with facial selectivity in the presence of transition-metal complexes. This is due to intrinsic angle strain on carbon–carbon double bonds such unsymmetrical bicyclic systems. During past decades considerable progress has been made area ring opening strained rings by employing concept C–H activation. short revi...
We have investigated dynamical heterogeneity in a highly supercooled liquid using molecular-dynamics simulations in three dimensions. Dynamical heterogeneity can be characterized by three quantities: correlation length ξ(4), intensity χ(4), and lifetime τ(hetero). We evaluated all three quantities consistently from a single order parameter. In a previous study [H. Mizuno and R. Yamamoto, Phys. ...
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