6305-63-1Relevant academic research and scientific papers
Computationally guided design of a readily assembled phosphite-thioether ligand for a broad range of pd-catalyzed asymmetric allylic substitutions
Biosca, Maria,Margalef, Jèssica,Caldentey, Xisco,Besora, Maria,Rodríguez-Escrich, Carles,Saltó, Joan,Cambeiro, Xacobe C.,Maseras, Feliu,Pàmies, Oscar,Diéguez, Montserrat,Pericàs, Miquel A.
, p. 3587 - 3601 (2018/04/14)
A modular approach employing indene as common starting material, has enabled the straightforward preparation in three reaction steps of P-thioether ligands for the Pd-catalyzed asymmetric allylic substitution. The analysis of a starting library of P-thioether ligands based on rational design and theoretical calculations has led to the discovery of an optimized anthracenethiol derivative with excellent behavior in the reaction of choice. Improving most approaches reported to date, this ligand presents a broad substrate and nucleophile scope. Excellent enantioselectivities have been achieved for a range of linear and cyclic allylic substrates using a large number of C-, N-, and O-nucleophiles (40 compounds in total). The species responsible for the catalytic activity have been further investigated by NMR in order to clearly establish the origin of the enantioselectivity. The resulting products have been derivatized by means of ring-closing metathesis or Pauson-Khand reactions to further prove the synthetic versatility of the methodology for preparing enantiopure complex structures.
Synthesis of Secondary Unsaturated Lactams via an Aza-Heck Reaction
Shuler, Scott A.,Yin, Guoyin,Krause, Sarah B.,Vesper, Caroline M.,Watson, Donald A.
supporting information, p. 13830 - 13833 (2016/11/06)
The preparation of unsaturated secondary lactams via the palladium-catalyzed cyclization of O-phenyl hydroxamates onto a pendent alkene is reported. This method provides rapid access to a broad range of lactams that are widely useful building blocks in alkaloid synthesis. Mechanistic studies support an aza-Heck-type pathway.
A new modular phosphite-pyridine ligand library for asymmetric Pd-catalyzed allylic substitution reactions: A study of the key Pd-π-allyl intermediates
Mazuela, Javier,Pàmies, Oscar,Diéguez, Montserrat
supporting information, p. 2416 - 2432 (2013/04/23)
A library of phosphite-pyridine ligands L1-L12 a-g has been successfully applied for the first time in the Pd-catalyzed allylic substitution reactions of several di- and trisubstituted substrates by using a wide range of C, N and O nucleophiles, among which are the little studied α-substituted malonates, β-diketones, and alkyl alcohols. The highly modular nature of this ligand library enables the substituents/configuration at the ligand backbone, and the substituents/configurations at the biaryl phosphite moiety to be easily and systematically varied. We found that the introduction of an enantiopure biaryl phosphite moiety played an essential role in increasing the versatility of the Pd-catalytic systems. Enantioselectivities were therefore high for several hindered and unhindered di- and trisubstituted substrates by using a wide range of C, N and O nucleophiles. Of particular note were the high enantioselectivities (up to>99 % ee) and high activities obtained for the trisubstituted substrates S6 and S7, which compare favorably with the best that have been reported in the literature. We have also extended the use of these new catalytic systems in alternative environmentally friendly solvents such as propylene carbonate and ionic liquids. Studies on the Pd-π-allyl intermediates provide a deeper understanding of the effect of ligand parameters on the origin of enantioselectivity. A library of phosphite-pyridine ligands has been successfully applied in the Pd-catalyzed allylic substitution reactions of several di- and trisubstituted substrates by using a wide range of C, N, and O nucleophiles. By carefully selecting the ligand components, high regio- and enantioselectivities (up to >99 % ee) and good activities have been achieved (see scheme). The NMR studies on the Pd-π-allyl intermediates provide a deeper understanding of the effect of ligand parameters on the origin of enantioselectivity. Copyright
Palladium-catalyzed addition of mono- and dicarbonyl compounds to conjugated dienes
Leitner, Andreas,Larsen, Jens,Steffens, Christian,Hartwig, John F.
, p. 7552 - 7557 (2007/10/03)
An inter molecular, palladium-catalyzed addition of the α-C-H bond of monocarbonyl and 1,3-dicarbonyl compounds to dienes has been developed, and an exploration of the scope of these reactions with a broad range of carbonyl compounds and nitriles was cond
Synthesis and initial SAR studies of 3,6-disubstituted pyrazolo[1,5-a]pyrimidines: A new class of KDR kinase inhibitors
Fraley, Mark E.,Hoffman, William F.,Rubino, Robert S.,Hungate, Randall W.,Tebben, Andrew J.,Rutledge, Ruth Z.,McFall, Rosemary C.,Huckle, William R.,Kendall, Richard L.,Coll, Kathleen E.,Thomas, Kenneth A.
, p. 2767 - 2770 (2007/10/03)
We have synthesized and evaluated the activity of 3,6-disubstituted pyrazolo[1,5-a]pyrimidines as a new class of KDR kinase inhibitors. Starting with screening lead 1, potency against isolated KDR was fully optimized with 3-thienyl and 4-methoxyphenyl substituents at the 6- and 3-positions (3g, KDR IC50=19 nM), respectively. The synthesis and SAR of these compounds are described.
Palladium-catalyzed asymmetric allylic alkylations of cycloalkenyl acetates with planar chiral phosphino-ferrocene carboxylic acids
You, Shu-Li,Luo, Yu-Mei,Deng, We-Ping,Hou, Xue-Long,Dai, Li-Xin
, p. 845 - 849 (2007/10/03)
New phosphino-ferrocene carboxylic acids with only planar chirality (Sp)-3 and (Sp)-4 have been synthesized conveniently from (S,Sp)-5 and (S,Sp)-7. They were used as ligands in palladium-catalyzed allylic alkylation of cycloalkenyl acetates. With ligand (Sp)-4, high yield and good ee were given for reactions of a series of cycloalkenyl acetates and nucleophiles.
Et3B-promoted, Pd(0)-catalyzed allylation of active methylene compounds with allylic alcohols
Tamaru, Yoshinao,Horino, Yoshikazu,Araki, Misato,Tanaka, Shuji,Kimura, Masanari
, p. 5705 - 5709 (2007/10/03)
Triethylborane promotes the Pd(0)-catalyzed allylation of active methylene compounds (Meldrum's acid and malonates) with a variety of allylic alcohols. The reaction proceeds smoothly at room temperature and provides the allylation products in good yield. (C) 2000 Elsevier Science Ltd.
Ring opening of cyclopropane in tricyclo[4.3.0.02,9]nonan-3-one with electrophile-nucleophile reagents
Fernandez-Mateos, A.,Alonso, J. J. Perez,Gonzales, R. Rubio
, p. 847 - 860 (2007/10/03)
Four tricyclo[4.3.0.02,9]nonan-3-one systems were treated with TBDMSI, TMSTFA and TMSTFA/NaSPh, affording different cyclopropane cleavage products, depending on the location of the substituent and the nature of the reagent.
Scope of the intramolecular titanocene-catalyzed Pauson-Khand type reaction
Hicks, Frederick A.,Kablaoui, Natasha M.,Buchwald, Stephen L.
, p. 5881 - 5898 (2007/10/03)
A Pauson-Khand type conversion of enynes to bicyclic cyclopentenones employing the commercially available precatalyst titanocene dicarbonyl is described. This methodology shows excellent functional group tolerance for a group 4 metallocene-catalyzed process. The scope and limitations of this cyclization with respect to 1,6-, 1,7- and 1,8-enynes with a variety of terminal alkyne substituents, chiral enynes, and enynes containing substituted olefins are described in detail. A mechanism involving carbonylation of an intermediate titanacyclopentene has been proposed.
Alkylation of β-dicarbonyl compounds with 1,2-dibromocyclohexane
Sadykkov,Nasibov,Muradova,Gasymov
, p. 310 - 312 (2007/10/03)
Alkylation of acetylacetone, ethyl acetoacetate, and diethyl malonate with 1,2-dibromocyclohexane in the presence of K2CO3 in DMSO occurs only as C-alkylation accompanied by dehydrobromination, whereas a similar reaction of dimedone
