- Oxidation of Primary Alcohols and Aldehydes to Carboxylic Acids via Hydrogen Atom Transfer
-
The oxidation of primary alcohols and aldehydes to the corresponding carboxylic acids is a fundamental reaction in organic synthesis. In this paper, we report a new chemoselective process for the oxidation of primary alcohols and aldehydes. This metal-free reaction features a new oxidant, an easy to handle procedure, high isolated yields, and good to excellent functional group tolerance even in the presence of vulnerable secondary alcohols and tert-butanesulfinamides.
- Tan, Wen-Yun,Lu, Yi,Zhao, Jing-Feng,Chen, Wen,Zhang, Hongbin
-
supporting information
p. 6648 - 6653
(2021/09/08)
-
- Use of Imidazo[1,5-a]pyridin-3-ylidene as a Platform for Metal-Imidazole Cooperative Catalysis: Silver-Catalyzed Cyclization of Alkyne-Tethered Carboxylic Acids
-
Silver complexes with 5-(4-(tert-butyl)-1H-imidazol-1-yl)-imidazo[1,5-a]pyridin-3-ylidene ligands were synthesized as metal-imidazole acid-base cooperative catalysts. Single crystal XRD analysis revealed that the silver atom was located in the vicinity of
- Rawat, Vishal Kumar,Higashida, Kosuke,Sawamura, Masaya
-
supporting information
p. 1631 - 1637
(2021/02/03)
-
- Gold-catalyzed Rapid Construction of Nitrogen-containing Heterocyclic Compound Library with Scaffold Diversity and Molecular Complexity
-
1,3-unsubstituted 2-(1H-indol-2-yl)ethanamines were employed for the first time to react with alkynoic acids (AAs) to achieve gold-catalyzed highly selective cascade reactions to furnish novel indole-fused skeletons. Furthermore, with this powerful gold catalytic system, a library of indole/pyrrole/thiophene/benzene/naphthalene/pyridine-based nitrogen-containing heterocyclic compounds (NCHCs) with scaffold diversity and molecular complexity was constructed rapidly using various amine nucleophiles (ANs) and diverse AAs as the building blocks. This general protocol features excellent selectivity, extraordinarily broad substrate scope, readily available inputs, good to high yields, high bond-forming efficiency, and step economy, thus providing a facile and efficient access to a variety of valuable nitrogen-containing heterocycles.
- Qiao, Jin,Jia, Xiuwen,Li, Pinyi,Liu, Xiaoyan,Zhao, Jingwei,Zhou, Yu,Wang, Jiang,Liu, Hong,Zhao, Fei
-
-
- Regioselectivity Influences in Platinum-Catalyzed Intramolecular Alkyne O-H and N-H Additions
-
The steric and electronic drivers of regioselectivity in platinum-catalyzed intramolecular hydroalkoxylation are elucidated. A branch point is found that divides the process between 5-exo and 6-endo selective processes, and enol ethers can be accessed in good yields for both oxygen heterocycles. The main influence arises from an electronic effect, where the alkyne substituent induces a polarization of the alkyne that leads to preferential heteroatom attack at the more electron-deficient carbon. The electronic effects are studied in other contexts, including hydroacyloxylation and hydroamination, and similar trends in directionality are predominant although not uniformly observed.
- Costello, Jeff P.,Ferreira, Eric M.
-
p. 9934 - 9939
(2019/12/24)
-
- Rapid Access to Thiolactone Derivatives through Radical-Mediated Acyl Thiol-Ene and Acyl Thiol-Yne Cyclization
-
A new synthetic approach to thiolactones that employs an efficient acyl thiol-ene (ATE) or acyl thiol-yne (ATY) cyclization to convert unsaturated thiocarboxylic acid derivatives into thiolactones under very mild conditions is described. The high overall yields, fast kinetics, high diastereoselectivity, excellent regiocontrol, and broad substrate scope of these reaction processes render this a very useful approach for diversity-oriented synthesis and drug discovery efforts. A detailed computational rationale is provided for the observed regiocontrol.
- McCourt, Ruairi O.,Dénès, Fabrice,Sanchez-Sanz, Goar,Scanlan, Eoin M.
-
p. 2948 - 2951
(2018/05/28)
-
- Palladium NNC Pincer Complex as an Efficient Catalyst for the Cycloisomerization of Alkynoic Acids
-
A two-step (nucleophilic substitution/palladation by oxidative addition) sequence provides a high-yielding access to a non-symmetrical palladium NNC pincer complex. A number of terminal and internal alkynoic acids with different substitution patterns at the α- and β-positions are regio- and diastereoselectively cycloisomerized to the corresponding exocyclic enol lactones in the presence of exceedingly low amounts of the latter palladium complex, so that unprecedented turnover numbers and frequencies ranging from 1,000,000 to 700,000 and from 41,667 to 9722 h?1, respectively, are achieved. The optimized protocol, based on the use of a catalytic amount of triethylamine as base, allows an easy real-time monitoring of the reaction by NMR spectroscopy. Several pieces of evidence in favor of the direct participation of the above pincer complex as the catalyst of the reaction have been gathered from kinetic and poisoning experiments. (Figure presented.).
- Conde, Nerea,SanMartin, Raul,Herrero, María Teresa,Domínguez, Esther
-
p. 3283 - 3292
(2016/10/21)
-
- Cycloisomerization of acetylenic acids to γ-alkylidene lactones using a palladium(II) catalyst supported on amino-functionalized siliceous mesocellular foam
-
Cycloisomerization of various γ-acetylenic acids to their corresponding γ-alkylidene lactones by the use of a heterogeneous Pd(II) catalyst supported on amino-functionalized siliceous mesocellular foam is described. Substrates containing terminal as well
- Nagendiran, Anuja,Verho, Oscar,Haller, Clemence,Johnston, Eric V.,Baeckvall, Jan-E.
-
p. 1399 - 1405
(2014/03/21)
-
- Gold-catalyzed cycloisomerization of 1,6-diyne carbonates and esters to 2,4a-dihydro-1 H-fluorenes
-
A synthetic method to prepare 2,4a-dihydro-1H-fluorenes efficiently from gold(I)-catalyzed 1,2-acyloxy migration/cyclopropenation/Nazarov cyclization of 1,6-diyne carbonates and esters is described. The suggested reaction pathway provides rare examples of [2,3]-sigmatropic rearrangement in this class of compounds as well as the involvement of an in situ formed cyclopropene intermediate in gold catalysis. Experimental and ONIOM(QM:QM′) [our own n-layered integrated molecular orbital and molecular mechanics(quantum mechanics:quantum mechanics′)] computational studies based on the proposed Au carbenoid species provide insight into this unique selectivity.
- Rao, Weidong,Koh, Ming Joo,Li, Dan,Hirao, Hajime,Chan, Philip Wai Hong
-
p. 7926 - 7932
(2013/06/27)
-
- The combination of relay and cooperative catalysis with a gold/palladium/brnsted acid ternary system for the cascade hydroamination/ allylic alkylation reaction
-
The combination of relay and cooperative catalysis with a gold/palladium/Brnsted acid ternary system renders a cascade hydroamination/allylic alkylation reaction to provide an unprecedented entry to pyrrolidine derivatives in high yields. Copyright
- Wu, Hua,He, Yu-Ping,Gong, Liu-Zhu
-
supporting information; experimental part
p. 975 - 980
(2012/05/20)
-
- Alkyne-mediated domino hydroformylation/double cyclization: Mechanistic insight and synthesis of (±)-tashiromine
-
A novel domino reaction, alkyne-mediated domino hydroformylation/double cyclization, has been developed for rapid preparation of indolizidine type alkaloids. DFT calculations were applied for rationales of reactivity and selectivity. A concise synthesis of tashiromine as the application of the methodology is also reported.
- Chiou, Wen-Hua,Lin, Yi-Huei,Chen, Guei-Tang,Gao, Yu-Kai,Tseng, Yu-Che,Kao, Chien-Lun,Tsai, Jui-Chi
-
p. 3562 - 3564
(2011/04/26)
-
- An effective synthetic entry to fused benzimidazoles via iodocyclization
-
A protocol for the synthesis of the fused heterocyclic polycyclic compounds pyrrole[1,2-a]benzimidazoles, piperidine[1,2-a]benzimidazoles and oxa-fused benzimidazoles using iodine and silver nitrate by an exo-dig or endo-dig cyclization pathway at room te
- Zhang, Xu,Zhou, Yu,Wang, Hengshuai,Guo, Diliang,Ye, Deju,Xu, Yungen,Jiang, Hualiang,Liu, Hong
-
p. 1429 - 1437
(2011/08/03)
-
- Copper-Free Sonogashira coupling in water with an amphiphilic resin-supported palladium complex
-
The palladium-catalyzed coupling reaction of aryl halides with terminal alkynes, the Sonogashira coupling, took place in water under copper-free conditions by use of an amphiphilic polystyrene-poly(ethylene glycol) (PS-PEG) resin-supported palladium-phosphine complex to give the corresponding aryl-substituted alkynes in high yields. The PS-PEG resin-supported palladium catalyst was recovered by simple filtration and reused four times without any loss of catalytic activity.
- Suzuka, Toshimasa,Okada, Yukari,Ooshiro, Kazumasa,Uozumi, Yasuhiro
-
experimental part
p. 1064 - 1069
(2010/03/25)
-
- Cycloaddition reactions of 1,3-diazabuta-1,3-dienes with alkynyl ketenes
-
The cycloaddition reactions of 'all-carbon' 1,3-diazabuta-1,3-dienes with a few conjugated and unconjugated alkynyl ketenes are described. The reactions provide some interesting azetidinones and dihydropyrimidinones bearing an alkynyl moiety. The regiochemistry of cycloadduct is related with the degree of conjugation of the alkynyl ketene. Moreover, two alternative approaches to 'all-carbon' 1,3-diazabuta-1,3-dienes are reported.
- Abbiati, Giorgio,Contini, Alessandro,Nava, Donatella,Rossi, Elisabetta
-
experimental part
p. 4664 - 4670
(2009/10/09)
-
- Cyclization of alkynoic acids with gold catalysts: a surprising dichotomy between AuI and AuIII
-
ω-Acetylenic acids, substituted or not at their acetylenic end, could be efficiently cyclized to γ- or δ-alkylidene lactones in the presence of AuCl and K2CO3. In contrast AuCl3 led to lactone dimers, probably through cycl
- Harkat, Hassina,Dembelé, Albert Yénimégué,Weibel, Jean-Marc,Blanc, Aurélien,Pale, Patrick
-
experimental part
p. 1871 - 1879
(2009/06/28)
-
- Intramolecular PIFA-mediated alkyne amidation and carboxylation reaction
-
(Chemical Equation Presented) The hypervalent iodine reagent PIFA promotes the intramolecular electrophilic cyclization of easily accessible alkynylamides and alkynyl carboxylic acids, leading to the formation of pyrrolidinone and lactone skeletons, respe
- Tellitu, Imanol,Serna, Sonia,Herrero, M. Teresa,Moreno, Isabel,Dominguez, Esther,SanMartin, Raul
-
p. 1526 - 1529
(2007/10/03)
-
- HISTONE DEACETYLASE INHIBITORS
-
Hormone refractory metastatic disease can be treated with an oxyamide-containing compound through the inhibition of HDAC1 or HDAC2.
- -
-
Page/Page column 18
(2008/06/13)
-
- The sonogashira reaction in water via an amphiphilic resin-supported palladium-phosphine complex under copper-free conditions
-
The Sonogashira reaction of aryl halides with terminal alkynes was catalyzed by an amphiphilic polystyrene-poly(ethylene glycol) (PS-PEG) resin-supported palladium-phosphine complex in water to give the corresponding aryl-substituted alkynes in high yields under copper-free conditions. Reaction of o-iodophenol with terminal alkynes under Sonogashira conditions gave benzofuran derivatives in one step.
- Uozumi, Yasuhiro,Kobayashi, Yukinari
-
-
- Histone deacetylase inhibitors
-
Histone deacetylase is a metallo-enzyme with zinc at the active site. Compounds having a zinc-binding moiety, such as, for example, a carboxylic acid group, can inhibit histone deacetylase. Histone deacetylase inhibition can repress gene expression, inclu
- -
-
-
- Synthesis of 3-arylpropenyl, 3-arylpropynyl and 3-arylpropyl 2-azetidinones as cholesterol absorption inhibitors: Application of the palladium-catalyzed arylation of alkenes and alkynes
-
A series of 3-(3'-arylpropenyl)-2-azetidinones 8a-8k and 3-(3'-arylpropynyl)-2-azetidinones 16m-16p were prepared by the palladium-catalyzed arylation of 3-(3'-propenyl)-2-azetidinone 7, or by arylation of 4-pentenoic acid, or via ethyl 4-pentynoate followed by 2-azetidinone ring construction. The unsaturated 2-azetidinones were transformed to their saturated analogs 9a-9p by catalytic hydrogenation. Azetidinones 8a-8k, 9a-9p, and 16m-16p were evaluated for their biological activity as cholesterol absorption inhibitors in hamsters. (C) 2000 Elsevier Science Ltd.
- Rosenblum, Stuart B.,Huynh, Tram,Afonso, Adriano,Davis Jr., Harry R.
-
p. 5735 - 5742
(2007/10/03)
-
- NEW FACILE SYNTHESIS OF SUBSTITUTED 2-BENZYLIDENEPYRROLIDINES BY THE ANIONIC CYCLIZATION OF δ-ALKYNYLAMINES
-
Treatment of δ-alkynylamines with butyllithium or lithium aluminum hydride brought about a facile anionic cyclization, giving high yields of the corresponding enamine pyrrolidines having an exo double bound.
- Tokuda, Masao,Fujita, Hirotake,Suginome, Hiroshi
-
p. 5353 - 5356
(2007/10/02)
-