59378-82-4Relevant articles and documents
Rapid “high” temperature batch and flow lithiation-trapping of N-Boc pyrrolidine
Kwong, Alice,Firth, James D.,Farmer, Thomas J.,O'Brien, Peter
supporting information, (2021/01/25)
The development of suitable reaction conditions for the rapid “high” temperature lithiation-trapping of N-Boc pyrrolidine under batch and flow conditions is described. For optimisation of batch conditions, the lithiation-trapping was explored using s-BuLi at temperatures of ?30 to 20 °C. Two new batch lithiation conditions were discovered using the biomass-derived, sustainable solvent, 2-MeTHF: diamine-free lithiation in 2-MeTHF gave α-substituted pyrrolidines in 50–69% yields at ?20 °C or 0 °C. The requirement for very short lithiation times is explained by the chemical instability of the lithiated intermediate at high temperatures. A practical flow chemistry reaction manifold (s-BuLi, TMEDA, THF, 0 °C, 5 s) has been developed which delivered an α-substituted pyrrolidine in 59% yield. This flow process opens up new opportunities for scaling-up of lithiation-trapping reactions of N-Boc heterocycles.
Boosting the hydrolytic stability of phosphite ligand in hydroformylation by the construction of superhydrophobic porous framework
Tang, Yongquan,Dong, Ke,Wang, Sai,Sun, Qi,Meng, Xiangju,Xiao, Feng-Shou
, (2019/06/05)
The development of a catalyst that delivers high activities and selectivities with excellent durability is of great importance. Numerous efficient catalysts suffer from the inherent hydrolysis liabilities, plaguing their practical applications. Herein, we show that this challenge can be tackled by constructing them into superhydrophobic porous frameworks, as exemplified by a water-sensitive phosphite ligand, tris(2-tert-butylphenyl) phosphite. The efficiency and long-term stability of the developed system are remarkably high in the hydroformylation of internal olefins after metalation with Rh species, superior to the corresponding homogeneous analogues. The significantly boosted hydrolytic stability allows for catalytic transformations using water as a green solvent, which not only facilitates the isolation of the products, but also furnishes the aldehydes with higher regioselectivities for the desired linear form in comparison with that operated under benchmark conditions using toluene as a reaction medium. Given these promising results, we anticipate the strategy advanced herein will form the basis for constructive perspectives in the enhancement of the water resistance of catalysts and the development of high performance hydroformylation catalysts.
AMINOPYRIDINE COMPOUNDS AND METHODS FOR THE PREPARATION AND USE THEREOF
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, (2018/12/02)
The present invention relates generally to therapeutics targeting the bacterium Porphyromonas gingivalis, including its proteases arginine gingipain A/B (Rgp), and their use for the treatment of disorders associated with P. gingivalis infection, including brain disorders such as Alzheimer's disease. In certain embodiments, the invention provides compounds according to Formula I and Formula III, as described herein, and pharmaceutically acceptable salts thereof.
Backbone-Modified Bisdiazaphospholanes for Regioselective Rhodium-Catalyzed Hydroformylation of Alkenes
Wildt, Julia,Brezny, Anna C.,Landis, Clark R.
, p. 3142 - 3151 (2017/09/05)
A series of tetraaryl bisdiazaphospholane (BDP) ligands were prepared varying the phosphine bridge, backbone, and substituents in the 2- and 5-positions of the diazaphospholane ring. The parent acylhydrazine backbone was transformed to an alkylhydrazine via a borane reduction procedure. These reduced ligands contained an all sp3 hybridized ring mimicking the all sp3 phospholane of (R,R)-Ph-BPE, a highly selective ligand in asymmetric hydroformylation. The reduced bisdiazaphospholane (red-BDP) ligands were shown crystallographically to have an increased C-N-N-C torsion angle - this puckering resembles the structure of (R,R)-Ph-BPE and has a dramatic influence on regioselectivity in rhodium catalyzed hydroformylation. The red-BDPs demonstrated up to a 5-fold increase in selectivity for the branched aldehyde compared to the acylhydrazine parent ligands. This work demonstrates a facile procedure for increased branched selectivity from the highly active and accessible class of BDP ligands in hydroformylation.
Photo-induced Substitutive Introduction of the Aldoxime Functional Group to Carbon Chains: A Formal Formylation of Non-Acidic C(sp3)?H Bonds
Kamijo, Shin,Takao, Go,Kamijo, Kaori,Hirota, Masaki,Tao, Keisuke,Murafuji, Toshihiro
supporting information, p. 9695 - 9699 (2016/08/10)
A photo-induced substitutive introduction of an aldoxime functional group to carbon chains was achieved using photo-excited 4-benzoylpyridine as a C(sp3)?H bond cleaving agent and arylsulfonyl oxime as an aldoxime precursor. The non-acidic C?H bonds in various substances, including cycloalkanes, ethers, azacycles, and cyclic sulfides, were chemoselectively converted at ambient temperature under neutral conditions. The present transformation is a formal formylation of non-acidic C(sp3)?H bonds in a single step.
One-Pot Three-Component Synthesis of Vicinal Diamines via In Situ Aminal Formation and Carboamination
Orcel, Ugo,Waser, Jerome
supporting information, p. 12881 - 12885 (2016/10/04)
A synthesis of vicinal diamines via in situ aminal formation and carboamination of allyl amines is reported. Employing highly electron-poor trifluoromethyl aldimines in their stable hemiaminal form was key to enable both a fast and complete aminal formation as well as the palladium-catalyzed carboamination step. The conditions developed allow the introduction of a wide variety of alkynyl, vinyl, aryl, and hetereoaryl groups with complete regioselectivity and high diastereoselectivity. The reaction exhibits a high functional-group tolerance. Importantly, either nitrogen atom of the imidazolidine products can be selectively deprotected, while removal of the aminal tether can be achieved in a single step under mild conditions to reveal the free diamine. We expect that this work will promote the further use of mixed aminal tethers in organic synthesis.
A rapid and efficient one-pot method for the reduction of N-protected α-amino acids to chiral α-amino aldehydes using CDI/DIBAL-H
Ivkovic, Jakov,Lembacher-Fadum, Christian,Breinbauer, Rolf
supporting information, p. 10456 - 10460 (2015/11/10)
N-Protected amino acids can be easily converted into chiral α-amino aldehydes in a one-pot reaction by activation with CDI followed by reduction with DIBAL-H. This method delivers Boc-, Cbz- and Fmoc-protected amino aldehydes from proteinogenic amino acids in very good isolated yields and complete stereointegrity.
FUSED RING COMPOUNDS AS HEPATITIS C VIRUS INHIBITORS, PHARMACEUTICAL COMPOSITIONS AND USES THEREOF
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Paragraph 00314; 00329; 00649; 00650; 00655, (2014/06/23)
Provided are fused tricyclic compounds effective to inhibit the function of the NS5A protein of formula (I), wherein X, X', Y, Y', A, A',Q1, Q2, R1-R4, X4, R5a, f and W are defined as in the description. Also provided herein are pharmaceutical compositions thereof, and uses in the manufacture of a medicament for treating HCV infection or a HCV disorder thereof.
BRIDGED RING COMPOUNDS AS HEPATITIS C VIRUS INHIBITORS, PHARMACEUTICAL COMPOSITIONS AND USES THEREOF
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Page/Page column 195; 196, (2014/09/16)
Provided herein is a compound of formula (I) or a stereoisomer, a geometric isomer, a tautomer, an N-oxide, a hydrate, a solvate, a metabolite, a pharmaceutically acceptable salt or a prodrug thereof, which can be used for treating HCV infection or a HCV disorder. Also provided herein are a pharmaceutical composition comprising the compound and the use of the compound and the pharmaceutical composition thereof, which can also be used for treating HCV infection or a HCV disorder.
Gold-catalyzed oxycyclization of allenic carbamates: Expeditious synthesis of 1,3-oxazin-2-ones
Alcaide, Benito,Almendros, Pedro,Quiros, M. Teresa,Fernandez, Israel
, p. 818 - 826 (2013/06/05)
A combined experimental and computational study on regioselective gold-catalyzed synthetic routes to 1,3-oxazinan-2-ones (kinetically controlled products) and 1,3-oxazin-2-one derivatives (thermodynamically favored) from easily accessible allenic carbamates has been carried out.
