Brønsted Base-Modulated Regioselective Pd-Catalyzed Intramolecular Aerobic Oxidative Amination of Alkenes: Formation of Seven-Membered Amides and Evidence for Allylic C−H Activation
作者:Liang Wu、Shuifa Qiu、Guosheng Liu
DOI:10.1021/ol900941t
日期:2009.6.18
A novelpalladium-catalyzed intramolecular aerobic oxidative allylic C−H amination of olefins has been developed. Brønsted base can modulate the regioselectivity, favoring the formation of 7-membered rings. Mechanistic studies using deuterium-labeled substrates as probes support a rate-determining allylic C−H activation/irreversible reductive elimination pathway.
2-Aza-4-(alkoxycarbonyl)spiro[4,5]-decan-3-one and a process for the production of it, starting either from cyclohexylidene malonic acid esters or cyclohexylidene cyanoalkylates. The cyclohexylidene malonic acid ester is reacted with hydrocyanic acid in the presence of a catalytic amount of alkali cyanide or with a stoichiometric amount of alkali cyanide, in an alcohol, and subsequently treated with an acid. The resultant (1-cyanocyclohexyl) malonic acid dialkyl ester is converted by catalytic hydrogenation into the product. The cyclohexylidene cyanoalkylate is reacted with a stoichiometric amount of alkali cyanide, in an alcohol or with hydrocyanic acid in the presence of a catalytic amount of an alkali cyanide. The resultant (1-cyanocyclohexyl)-cyanoacetic acid alkyl ester is reacted in an alcohol in an acid to provide (1-cyanocyclohexyl) malonic acid dialkyl ester. The later ester is converted by catalytic hydrogenation into the product. Process of using the product for the production of 1-(aminomethyl)cyclohexane acetic acid by converting the product with HCl or sulfuric acid at an elevated temperature.
Organic photocatalysis for the radical couplings of boronic acid derivatives in batch and flow
作者:Fabio Lima、Lars Grunenberg、Husaini B. A. Rahman、Ricardo Labes、Joerg Sedelmeier、Steven V. Ley
DOI:10.1039/c8cc02169d
日期:——
We report an acridium-based organic photocatalyst as an efficient replacement for iridium-based photocatalysts to oxidise boronic acid derivatives by a single electron process. Furthermore, we applied the developed catalytic system to the synthesis of four active pharmaceutical ingredients (APIs). A straightforward scale up approach using continuous flow photoreactors is also reported affording gram
Enantioselective Catalyst Systems from Copper(II) Triflate and BINOL–Silanediol
作者:Yong Guan、Jonathan W. Attard、Michael D. Visco、Thomas J. Fisher、Anita E. Mattson
DOI:10.1002/chem.201801304
日期:2018.5.17
Silanediol and copper catalysis are merged, for the first time, to create an enhanced Lewis acid catalyst system for enantioselective heterocycle functionalization. The promise of this silanediol and copper catalyst combination is demonstrated in the enantioselective addition of indoles to alkylidene malonates to give rise to the desirable adducts in excellent yield and high enantiomeric excess. From
In the presence of titanium tetrachloride and pyridine in THF, diethyl malonate undergoes condensation with aliphatic and aromatic ketones. The yields of the resulting α,β-unsaturated compounds are good even in cases, where other condensation methods are unsuccessful. Products, resulting from α-mono-, α,α-, α,α′-di- and α,α,α-trihalogeno ketones are probably of special interest as useful intermediates