- [2+2] Photodimerization of Stilbazoles Promoted by Oxalic Acid in Suspension
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In this study, a very simple technique to perform efficiently photodimerization of some vinylpyridines is reported. By irradiating a stirred mixture of several stilbazoles with solid oxalic acid dihydrate dispersed in a nonpolar (i.e., cyclohexane) or moderately polar (benzene, dichloromethane, dioxane) solvent, the corresponding dimeric cyclobutane adducts were obtained in high yields and excellent regio- and stereoselectivities. The strategy could also be applied successfully to oily, waxy, or even insoluble stilbazoles. Moreover, the oxalic acid loading could be lowered to substoichiometric amounts. When further optimizations were needed, our strategy was found to be highly flexible to identify other oligocarboxylic acids as alternative additives to improve, or even overturn, the regioselectivity. Oxalic acid and other oligocarboxylic acids were found to be capable of orienting more than 50 stilbazoles toward photodimerization under these conditions.
- Nguyen, Thanh Binh,Nguyen, Tuan Minh,Retailleau, Pascal
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supporting information
p. 4682 - 4689
(2020/04/15)
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- Palladium- meta -terarylphosphine catalyst for the Mizoroki-Heck reaction of (hetero)aryl bromides and functional olefins
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The evolutionary meta-terarylphosphine ligand architecture of Cy?Phine was recently shown to be a key feature that imposed outstanding performance in palladium-catalyzed copper-free Sonogashira applications. Herein, the Pd-Cy?Phine combination has similar
- Tay, Daniel Weiliang,Jong, Howard,Lim, Yee Hwee,Wu, Wenqin,Chew, Xinying,Robins, Edward G.,Johannes, Charles W.
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p. 4054 - 4063
(2015/05/05)
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- Can Palladium Acetate Lose Its "saltiness"? Catalytic Activities of the Impurities in Palladium Acetate
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Commercially available palladium acetate often contains two major impurities, whose presence can impact the overall catalytic efficacy. This systematic study provides a comparison of the differences in catalytic activity of pure palladium acetate, Pd3(OAc)6, with the two impurities: Pd3(OAc)5(NO2) and polymeric [Pd(OAc)2]n in a variety of cross-coupling reactions. The solid state 13C NMR spectra of all three compounds in conjunction with DFT calculations confirm their reported geometries.
- Carole, William A.,Bradley, Jonathan,Sarwar, Misbah,Colacot, Thomas J.
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supporting information
p. 5472 - 5475
(2015/11/18)
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- Heck cross-coupling of vinyl heteroaromatic compounds with aryl and heteroaryl halides using Pd(II) complex under phosphine-free conditions
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The palladium-catalyzed cross-coupling reaction of vinyl heteroaromatic compounds with aryl bromides and heteroaryl bromides is described using air and moisture stable N,N′,N″,O-tetrafunctional Pd catalyst under phosphine-free conditions. As a result a variety of trans-1,2-disubstituted vinyl heterocycles were obtained in high to good yields.
- Annapurna, Manne,Vishnuvardhan Reddy,Singh, Surya Prakash,Kantam, Mannepalli Lakshmi
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p. 10940 - 10945
(2014/01/06)
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- Utilities of olefin derivatives
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Compounds having an activity to enhance the expression of apoAI are provided. Compounds of formula (I): in which Ar1 and Ar2 are independently a phenyl, naphthyl, or monocyclic or bicyclic aromatic heterocyclic group, which may be optionally substituted; —X— is —N═CZ2-, —CY2═CZ2-, —CY2Y3—CHZ2-, —S—, —O—, or the like; Y1, Y2, Y3, Z1 and Z2 are independently a hydrogen, a halogen, a lower alkyl, a phenyl, or the like; Z1 and Z2 may be independently a linker group that may combine with Ar2 and Ar1 to form a condensed ring; m is 0 or 1, and n is 0 to 2; a prodrug thereof, a pharmaceutically acceptable salt or solvate of them; are disclosed.
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Page/Page column 20; 30
(2008/06/13)
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