Polymer brushes are found in biomedical and industrial technologies, where they exhibit functionalities considerably dependent on polymer brush-solvent-analyte interactions. It remains a difficult challenge to quickly analyze solvent-swollen polymer brushes, both at the solvent-polymer brush interface and in the brush interior, as well as to monitor the kinetics of interaction of solvent-swollen brushes with key analytes. Here, we demonstrate the novel use of silicon photonic microring resonators to characterize in situ swollen polymer brush-analyte interactions. By monitoring resonant wavelength shifts, we find that brush-solvent-analyte interaction parameters can be extracted from a single set of data or from successive analyte introductions using a single brush-coated sensor. The partition coefficient of three industrially relevant plasticizers into hydrophobic and hydrophilic brushes was determined and found to be in agreement with known solubility trends. We found that the diffusion coefficient of the plasticizer into the brush decreases as brush thickness increases, supporting a model of a dense inner brush layer and diffuse outer layer. pKa's of pH-sensitive brushes were determined on the microring resonator platform; upon increasing the dry brush thickness, the pKa for poly(2-dimethylamino ethyl methacrylate) decreased from 8.5 to approach the bulk material pKa of 7.3 and showed dependence on the presence and concentration of salt. These proof-of-concept experiments show how the surface-sensitive nature of the microring resonator detection platform provides valuable information about the interaction of the polymer brushes with the solvents and analytes, not easily accessed by other techniques.

Both fused and bridged tetracyclic scaffolds characteristic of endiandric acid-type natural products have been prepared in just seven steps each (longest linear sequence) from Burke's commercial cis-2-bromovinylboronic acid MIDA ester. Three iterative Suzuki–Miyaura couplings using MIDA boronates, including the first such example of a Z–Z coupling, trigger an 8π/6π-electrocyclization cascade. The mixture of endo and exo bicycles thus formed are elaborated into tetracycles via Horner–Wadsworth–Emmons and Diels–Alder reactions. In the process, the endo and exo diastereomers interconvert to ultimately deliver the desired products.

ChemInformVolume 47, Issue 3 Natural Products ChemInform Abstract: Direct, Biomimetic Synthesis of (+)-Artemone (I) via a Stereoselective, Organocatalytic Cyclization. Eric D. Nacsa, Eric D. Nacsa Dep. Chem., Harvey Mudd Coll., Claremont, CA 91711, USASearch for more papers by this authorBrian C. Fielder, Brian C. Fielder Dep. Chem., Harvey Mudd Coll., Claremont, CA 91711, USASearch for more papers by this authorShannon P. Wetzler, Shannon P. Wetzler Dep. Chem., Harvey Mudd Coll., Claremont, CA 91711, USASearch for more papers by this authorVeerasak Srisuknimit, Veerasak Srisuknimit Dep. Chem., Harvey Mudd Coll., Claremont, CA 91711, USASearch for more papers by this authorJonathan P. Litz, Jonathan P. Litz Dep. Chem., Harvey Mudd Coll., Claremont, CA 91711, USASearch for more papers by this authorMary J. Van Vleet, Mary J. Van Vleet Dep. Chem., Harvey Mudd Coll., Claremont, CA 91711, USASearch for more papers by this authorKim Quach, Kim Quach Dep. Chem., Harvey Mudd Coll., Claremont, CA 91711, USASearch for more papers by this authorDavid A. Vosburg, David A. Vosburg Dep. Chem., Harvey Mudd Coll., Claremont, CA 91711, USASearch for more papers by this author Eric D. Nacsa, Eric D. Nacsa Dep. Chem., Harvey Mudd Coll., Claremont, CA 91711, USASearch for more papers by this authorBrian C. Fielder, Brian C. Fielder Dep. Chem., Harvey Mudd Coll., Claremont, CA 91711, USASearch for more papers by this authorShannon P. Wetzler, Shannon P. Wetzler Dep. Chem., Harvey Mudd Coll., Claremont, CA 91711, USASearch for more papers by this authorVeerasak Srisuknimit, Veerasak Srisuknimit Dep. Chem., Harvey Mudd Coll., Claremont, CA 91711, USASearch for more papers by this authorJonathan P. Litz, Jonathan P. Litz Dep. Chem., Harvey Mudd Coll., Claremont, CA 91711, USASearch for more papers by this authorMary J. Van Vleet, Mary J. Van Vleet Dep. Chem., Harvey Mudd Coll., Claremont, CA 91711, USASearch for more papers by this authorKim Quach, Kim Quach Dep. Chem., Harvey Mudd Coll., Claremont, CA 91711, USASearch for more papers by this authorDavid A. Vosburg, David A. Vosburg Dep. Chem., Harvey Mudd Coll., Claremont, CA 91711, USASearch for more papers by this author First published: 14 July 2016 https://doi.org/10.1002/chin.201603173Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume47, Issue3December 29, 2015 RelatedInformation

We present a four-step synthesis of (+)-artemone from (-)-linalool, featuring iminium organocatalysis of a doubly diastereoselective conjugate addition reaction. The strategy follows a proposed biosynthetic pathway, rapidly generates stereochemical complexity, uses no protecting groups, and minimizes redox manipulations.