5-Iodouracil-substituted RNA and DNA were crosslinked regiospecifically to associated proteins in yields of 70 to 94% of bound nucleic acid. Irradiation of the iodouracil chromophore with monochromatic, long-wavelength ultraviolet radiation (325 nanometers) eliminates excitation of other nucleic acid and protein chromophores. The combination of high… (More)
Alkene and alkyne hydroacylation reactions are archetypal examples of simple addition processes that display excellent atom economy.  Both reactions result in the formation of a new CÀC bond and deliver synthetically useful carbonyl-containing products.  In recent years, there has been considerable interest in converting these processes into… (More)
For over 30 years, rapamycin has generated a sustained and intense interest from the scientific community as a result of its exceptional pharmacological properties and challenging structural features. In addition to its well known therapeutic value as a potent immunosuppressive agent, rapamycin and its derivatives have recently gained prominence for the… (More)
A redox-neutral palladium(II)-catalyzed conversion of aryl, heteroaryl, and alkenyl boronic acids into sulfinate intermediates, and onwards to sulfones and sulfonamides, has been realized. A simple Pd(OAc)2 catalyst, in combination with the sulfur dioxide surrogate 1,4-diazabicyclo[2.2.2]octane bis(sulfur dioxide) (DABSO), is sufficient to achieve rapid and… (More)
Rhodium(I) catalysts incorporating small bite-angle diphosphine ligands, such as (Cy2 P)2 NMe or bis(diphenylphosphino)methane (dppm), are effective at catalysing the union of aldehydes and propargylic amines to deliver the linear hydroacylation adducts in good yields and with high selectivities. In situ treatment of the hydroacylation adducts with p-TSA… (More)
A Rh-catalyst system based on the asymmetric ligand (t)Bu2PCH2P(o-C6H4OMe)2 is reported that allows for the hydroacylation of challenging internal alkenes with β-substituted aldehydes. Mechanistic studies point to the stabilizing role of both excess alkene and the OMe-group.
We describe a method for the synthesis of sulfonamides through the combination of an organometallic reagent, a sulfur dioxide equivalent, and an aqueous solution of an amine under oxidative conditions (bleach). This simple reaction protocol avoids the need to employ sulfonyl chloride substrates, thus removing the limitation imposed by the commercial… (More)
Sulfonyl-derived functional groups populate a broad range of useful molecules and materials, and despite a variety of preparative methods being available, processes which introduce the most basic sulfonyl building block, sulfur dioxide, using catalytic methods, are rare. Described herein is a simple reaction system consisting of the sulfur dioxide surrogate… (More)
The addition of Grignard reagents or organolithium reagents to the SO2-surrogate DABSO generates a diverse set of metal sulfinates, suitable for direct conversion to sulfone products. The metal sulfinates can be trapped in situ with a wide range of C-electrophiles, including alkyl, allyl, and benzyl halides, epoxides, and (hetero)aryliodoniums.
Aryl, heteroaryl, and alkenyl sulfones play a prominent role in organic and medicinal chemistry. Not only are they versatile intermediates in organic synthesis  , but they are also of particular pharmaceutical relevance, and exhibit an extensive and broad range of biological activities (Scheme 1).  In addition, sulfone-containing polymers display… (More)