16535-88-9Relevant academic research and scientific papers
Copper-Catalyzed Formation of α-Alkoxycycloalkenones from N-Tosylhydrazones
Su, Naijing,Theorell, Juliana A.,Wink, Donald J.,Driver, Tom G.
supporting information, p. 12942 - 12946 (2015/11/02)
The combination of 20 mol % of copper iodide and lithium tert-butoxide triggers the formation of a broad range of substituted, functionalized α-alkoxy 2H-naphthalenones from readily available N-tosylhydrazones. The data suggests that this transformation occurs through cycloaddition of a copper carbenoid with an ester, followed by a Lewis acid-catalyzed [1,2] alkyl shift of the in situ generated alkoxyepoxide intermediate. The combination of 20 mol % of copper iodide and lithium tert-butoxide triggers the formation of a broad range of substituted, functionalized α-alkoxy 2H-naphthalenones from readily available N-tosylhydrazones. The reaction proceeds by the cycloaddition of a copper carbenoid with an ester, and a subsequent Lewis acid-catalyzed [1,2] alkyl shift of the in situ generated alkoxyepoxide intermediate.
Arynes double bond insertion/nucleophilic addition with vinylogous amides and carbodiimides
Wu, Chao,Li, Ran,Tang, Huarong,Fu, Haixing,Ren, Hailong,Wang, Xuemei,Wu, Chunrui,Shi, Feng
, p. 1344 - 1355 (2014/03/21)
Arynes are shown to insert into some C=X double bonds, leading to benzannulated four-membered rings. The strain of these rings allow for a ready, spontaneous opening to afford o-quinomethide analogues. Subsequent nucleophilic addition re-aromatizes the intermediates to achieve ortho-difunctionalization of arynes. In this report, we describe the aryne insertion into the C=C double bonds of vinylogous amides and the C=N double bonds of carbodiimides. The correlation and comparison with aryne single bond insertion chemistry will be discussed. Computational studies for the ring-opening step, as well as the nature of the o-quinomethide intermediates, will also be discussed.
Expedient synthesis of 3-hydroxyisoquinolines and 2-hydroxy-1,4- naphthoquinones via one-pot aryne acyl-alkylation/condensation
Allan, Kevin M.,Hong, Boram D.,Stoltz, Brian M.
supporting information; experimental part, p. 4960 - 4964 (2010/02/15)
A convenient method is disclosed for the synthesis of both 3-hydroxyisoquinolines and 2-hydroxy-1,4-naphthoquinones from β-ketoesters using a one-pot aryne acyl-alkylation/condensation procedure. When performed in conjunction with a one-step method for the synthesis of the β-ketoester substrates, this method provides a new route to these polyaromatic structures in only two steps from commercially available carboxylic acid starting materials. The utility of this approach is demonstrated in the synthesis of the atropisomeric P,N-ligand, QUINAP. The Royal Society of Chemistry 2009.
The direct acyl-alkylation of arynes
Tambar, Uttam K.,Stoltz, Brian M.
, p. 5340 - 5341 (2007/10/03)
An efficient and mild acyl-alkylation of arynes is described. The method is used to synthesize medium-sized carbocycles by the ring-expansion of cyclic β-ketoesters. Copyright
Photochemical preparation of highly functionalized 1-indanones
Wessig, Pablo,Glombitza, Clemens,Mueller, Gunnar,Teubner, Janek
, p. 7582 - 7591 (2007/10/03)
A series of o-alkylphenyl alkyl ketones 1 were synthesized by different methods. The presence of a leaving group X adjacent to the carbonyl group is the special peculiarity of these ketones. Upon irradiation the keto carbonyl group of these compounds undergoes an n-π* excitation followed by a 1,5-hydrogen migration from the o-alkyl substituent to the carbonyl oxygen atom. The thus formed 1,4-diradicals are subject to a very rapid elimination of acid HX, giving 1,5-diradicals. We called this process spin center shift. After intersystem crossing these diradicals cyclize to 1-indanones 20 in good yields. Depending on the solvent and on substituents, o-alkoxyalkyl ketones 22 or benzo-[c]furanes 21 are obtained as byproducts. The mechanism of the cyclization was elucidated by quantum chemical calculations and kinetic measurements.
Palladium mediated total synthesis of o-acetylphenylacetic acids: A general route to indolo[2,3-b]naphthalene-6,11-diones
Cruces, Jacobo,Estévez, Juan C,Castedo, Luis,Estévez, Ramón J
, p. 4825 - 4827 (2007/10/03)
Here we describe a new, efficient general synthesis of o-acetylphenylacetic acids by Heck palladium-catalyzed arylation of n-butyl vinyl ether with o-bromophenylacetic acids, and its application to the synthesis of indolo[2,3-b]naphthalene-6,11-diones.
Reactions of carbonyl compounds in basic solutions. Part 21. The mechanisms of the alkaline hydrolysis of substituted methyl 2-(2-oxopropyl)- and 2-(2-oxo-2-phenylethyl)-benzoates and 2-(2-acetylphenyl)- and 2-(2-benzoylphenyl)-acetates
Bowden, Keith,Byrne, Jane M.
, p. 2203 - 2206 (2007/10/03)
Rate coefficients have been measured for the alkaline hydrolysis of methyl 2-[2-oxo-2-(3- or 4-substituted phenyl)ethyl]benzoates, 2-[2-(3- or 4-substituted benzoyl)phenyl]acetates,2-(2-oxopropyl) and 2-(1,1-dimethyl-2- oxopropyl)benzoates, 2-(2-acetylphenyl)acetate and 2-(2-acetylphenyl)-2,2- dimethylacetates in 70% (v/v) dioxane-water at 30.0 °C. Those for the six parent esters were also measured at 45.0 and 60.0 °C and the enthalpies and entropies of activation have been evaluated. The relative rates of hydrolysis, activation parameters and substituent effects have been used to demonstrate neighbouring participation by the keto-carbonyl groups in the alkaline hydrolysis of the esters under study. For comparable systems, participation by six-membered ring intermediates appears somewhat less advantageous than five-membered.
