Kevin H. Shaughnessy

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Water is truly ubiquitous. Approximately 80% of the earth’s surface is covered by water, although only 1% of this is drinkable water. Water is the solvent of life and makes up about 60% of the mass of the human body. The majority of synthetic organic chemistry carried out in research laboratories or industrial processes utilizes organic solvents, however.(More)
[reaction: see text]. Sterically demanding, water-soluble alkylphosphines have been found to give highly active catalysts for Suzuki coupling of aryl bromides in aqueous solvents. A variety of aryl bromides and boronic acids were coupled in excellent yield. Turnover numbers up to 734 000 mmol/mmol Pd have been achieved under mild conditions.
[reaction: see text] Sterically demanding, sulfonated arylphosphines TXPTS and TMAPTS have been applied to the aqueous-phase Heck and Suzuki coupling of aryl bromides. TXPTS provides good yields of Heck coupling products from aryl bromides at 80 degrees C, while both TMAPTS and TPPTS gave significantly less active catalysts. TXPTS is the first ligand to(More)
In the Suzuki arylations of unprotected halonucleosides in aqueous media, 8-bromo-2'-deoxyguanosine (8BrdG) couplings were slower to reach completion than the corresponding 8-bromo-2'-deoxyadenosine (8BrdA) couplings. The guanine moiety has an acidic proton, which under our Suzuki conditions (pH congruent with 10) may be deprotonated to give an anion that(More)
Synthetic modification of nucleoside structures provides access to molecules of interest as pharmaceuticals, biochemical probes, and models to study diseases. Covalent modification of the purine and pyrimidine bases is an important strategy for the synthesis of these adducts. Palladium-catalyzed cross-coupling is a powerful method to attach groups to the(More)
In this unit, an efficient method for the synthesis of alkyne-modified nucleosides in an aqueous solvent system is described. The method allows direct palladium-catalyzed alkynylation of readily available unprotected 8-bromo-2'-deoxyguanosine (8-BrdG), 8-bromo-2'-deoxyadenosene (8-BrdA), 8-bromoadenosine (8-BrA), and 5-iodo-2'-deoxyuridine (5-IdU)(More)
The air-stable complex Pd(η(3)-allyl)(DTBNpP)Cl (DTBNpP = di(tert-butyl)neopentylphosphine) serves as a highly efficient precatalyst for the arylation of amines and enolates using aryl bromides and chlorides under mild conditions with yields ranging from 74% to 98%. Amination reactions of aryl bromides were carried out using 1-2 mol %(More)
Di(tert-butyl)neopentylphosphine (DTBNpP) in combination with palladium sources provided catalysts with comparable or better activity for the Hartwig-Buchwald amination of aryl bromides than tri(tert-butyl)phosphine (TTBP) under mild conditions. DTBNpP also provided effective catalysts for amination reactions of aryl chlorides at elevated temperatures.(More)
Metal-catalyzed cross-coupling reactions have developed into a standard component of the synthetic chemist’s toolbox [1–4]. These reactions date to thework ofUllmann and Goldberg in the early 1900s on copper-promoted C–C and C–heteroatom bond formations. Copper remained the catalyst of choice for these reactions until the pioneeringwork ofHeck, Suzuki,(More)