14171-89-2Relevant articles and documents
Manganese-Catalyzed Hydroarylation of Unactivated Alkenes
Liu, Ting,Wang, Congyang,Yang, Yunhui
supporting information, p. 14256 - 14260 (2020/07/13)
Transition-metal-catalyzed hydroarylation of unactivated alkenes with strategic use of remote coordinating functional groups has received significant attention recently to address the issues of both low reactivity and poor selectivity. The bidentate 8-aminoquinoline amide group is the most successfully adopted in unactivated alkenes for Pd and Ni catalysis. We describe the first manganese-catalyzed hydroarylation of unactivated alkenes bearing diverse simple functionalities with arylboronic acids. A series of δ- and γ-arylated amides, ketones, pyridines, and amines was accessed with excellent regioselectivity and in high yields. Hydroalkenylation of unactivated alkenes was also shown to be applicable under this manganese-catalysis regime. The method features earth-abundant manganese catalysis, easily available substrates, broad functional-group tolerance, and excellent regioselective control.
Chiral isoxazolidine-mediated stereoselective umpolung α-phenylation of methyl ketones
Takeda, Norihiko,Furuishi, Mizuki,Nishijima, Yuri,Futaki, Erika,Ueda, Masafumi,Shinada, Tetsuro,Miyata, Okiko
supporting information, p. 8940 - 8943 (2018/12/10)
An effective asymmetric α-phenylation of methyl ketones with triphenylaluminium in the presence of (+)-benzopyranoisoxazolidine has been developed. The reaction proceeds via the in situ formation of a chiral N-alkoxyenamine and the subsequent diastereoselective nucleophilic phenylation to provide α-phenylated products in moderate to good yields, with high enantioselectivities.
Effects of lipophilicity, protecting group and stereochemistry on the antimalarial activity of carbohydrate-derived thiochromans
Madumo, Gilbert K.,Moshapo, Paseka T.,Kinfe, Henok H.
, p. 817 - 833 (2018/01/10)
A series of novel carbohydrate-derived thiochromans has been successfully synthesized in order to investigate the influence of alkyl substituents on the aromatic ring of the thiophenol moiety in addition to the effect of protecting groups and stereochemistry on the sugar component of the target molecules. Results from the evaluation of the thiochromans for their antimalarial activity against the chloroquine-sensitive (3D7) strain of Plasmodium falciparum suggest that the presence of short chain alkyl substituents, a benzyl ether protecting group and equatorial orientation of the C-4 substituent on the sugar moiety are crucial structural features that impart high antimalarial activity.
Organic photocatalysis for the radical couplings of boronic acid derivatives in batch and flow
Lima, Fabio,Grunenberg, Lars,Rahman, Husaini B. A.,Labes, Ricardo,Sedelmeier, Joerg,Ley, Steven V.
supporting information, p. 5606 - 5609 (2018/06/04)
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 an hour throughput.
2-AMINO-1,3,4-THIADIAZINE AND 2-AMINO-1,3,4-OXADIAZINE BASED ANTIFUNGAL AGENTS
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Page/Page column 51, (2017/02/09)
The invention provides a compound which is a diazine of formula (I) or a tautomer thereof, or a pharmaceutically acceptable salt thereof, for use as an antifungal agent: (I) wherein X, N', C', A and E are as defined herein. The invention also provides a compound of Formula (I) as defined herein.
Hydrogen-transfer reduction of α,β-unsaturated carbonyl compounds catalyzed by naphthyridine-functionalized N-heterocyclic carbene complexes
Huang, Hsiao-Ching,Ramanathan, Mani,Liu, Yi-Hong,Peng, Shie-Ming,Liu, Shiuh-Tzung
, (2017/07/25)
Substitution of silver complex of 2-chloro-7-(mesitylimidazolylidenylmethyl)naphthyridine (NpNHC) with palladium(II), rhodium(I) and iridium(I) metal precursors provided [Pd(C,N-NpNHC)(η3-allyl)](BF4) (5), RhCl(COD)(C-NpNHC) (6a) and IrCl(COD)(C-NpNHC) (6b), respectively. Abstraction of chloride from 6a and 6b with AgBF4 provided the chelation complexes [Rh(COD)(C,N-NpNHC)](BF4) (7a) and Ir(COD)(C,N-NpNHC)(BF4) (7b), respectively. All complexes were characterized using NMR and elemental analyses and the structural details of 5 and 6a were further confirmed using X-ray crystallography. In catalytic activity studies, complex 5 was found to be an effective catalyst in the hydrogen-transfer reduction of α,β-unsaturated carbonyl compounds into the corresponding saturated carbonyl compounds.
A Lewis Base Catalysis Approach for the Photoredox Activation of Boronic Acids and Esters
Lima, Fabio,Sharma, Upendra K.,Grunenberg, Lars,Saha, Debasmita,Johannsen, Sandra,Sedelmeier, Joerg,Van der Eycken, Erik V.,Ley, Steven V.
supporting information, p. 15136 - 15140 (2017/11/20)
We report herein the use of a dual catalytic system comprising a Lewis base catalyst such as quinuclidin-3-ol or 4-dimethylaminopyridine and a photoredox catalyst to generate carbon radicals from either boronic acids or esters. This system enabled a wide range of alkyl boronic esters and aryl or alkyl boronic acids to react with electron-deficient olefins via radical addition to efficiently form C?C coupled products in a redox-neutral fashion. The Lewis base catalyst was shown to form a redox-active complex with either the boronic esters or the trimeric form of the boronic acids (boroxines) in solution.
A simple route to 1,4-addition reactions by Co-catalyzed reductive coupling of organic tosylates and triflates with activated alkenes
Hsieh, Jen-Chieh,Chu, Yi-Hua,Muralirajan, Krishnamoorthy,Cheng, Chien-Hong
, p. 11584 - 11587 (2017/10/27)
An efficient Co-catalyzed 1,4-addition reaction of alkyl/aryl triflates and tosylates with activated alkenes is described. In this reaction, an air-stable cobalt(ii) complex, a mild reducing agent Zn and a simple proton source (H2O) are used. A radical mechanism for the addition of alkyl tosylates to activated alkenes is likely involved.
Hydrodecarboxylation of Carboxylic and Malonic Acid Derivatives via Organic Photoredox Catalysis: Substrate Scope and Mechanistic Insight
Griffin, Jeremy D.,Zeller, Mary A.,Nicewicz, David A.
supporting information, p. 11340 - 11348 (2015/09/21)
A direct, catalytic hydrodecarboxylation of primary, secondary, and tertiary carboxylic acids is reported. The catalytic system consists of a Fukuzumi acridinium photooxidant with phenyldisulfide acting as a redox-active cocatalyst. Substoichiometric quantities of Hünigs base are used to reveal the carboxylate. Use of trifluoroethanol as a solvent allowed for significant improvements in substrate compatibilities, as the method reported is not limited to carboxylic acids bearing α heteroatoms or phenyl substitution. This method has been applied to the direct double decarboxylation of malonic acid derivatives, which allows for the convenient use of dimethyl malonate as a methylene synthon. Kinetic analysis of the reaction is presented showing a lack of a kinetic isotope effect when generating deuterothiophenol in situ as a hydrogen atom donor. Further kinetic analysis demonstrated first-order kinetics with respect to the carboxylate, while the reaction is zero-order in acridinium catalyst, consistent with another finding suggesting the reaction is light limiting and carboxylate oxidation is likely turnover limiting. Stern-Volmer analysis was carried out in order to determine the efficiency for the carboxylates to quench the acridinium excited state.
Palladium on charcoal as a catalyst for stoichiometric chemo- and stereoselective hydrosilylations and hydrogenations with triethylsilane
Tuokko, Sakari,Pihko, Petri M.
, p. 1740 - 1751 (2015/02/19)
Stoichiometric quantities of triethylsilane in the presence of activated Pd/C as the catalyst can be used to effect chemo-, regio-, and stereoselective hydrosilylation and transfer hydrogenation reactions. α,β-Unsaturated aldehydes and ketones are selectively hydrosilylated to give the corresponding enol silanes or transfer hydrogenated to give the saturated carbonyl compounds in the presence of other reducible functional groups.
