General transfer hydrogenation procedure S6 Conversion monitoring of 4-phenyl-2-butanol dehydrogenation S7 General transfer dehydrogenation procedure S8 Product inhibition experimental details S8-S9 NMR experiments S9-S10 N-Benzylideneaniline reduction procedure S10-S11 References S11 NMR Spectra S12-S25 S2 General Methods. Compound 3 was prepared according to the literature procedure. S1 All commercially available chemicals and anhydrous solvents were used as received, and all reactions were done under an atmosphere of nitrogen unless otherwise noted. Reagent grade isopropanol and acetone (for the transfer hydrogenations and dehydrogenations) were degassed by bubbling N2 through them for at least 15 minutes prior to use, but no attempt was made to remove residual water. NMR spectra were recorded at rt (approx. 22 °C) unless otherwise noted on a Bruker Avance 400 MHz FT-NMR spectrometer. 13 C NMR spectra (100 MHz) were all proton decoupled. Chemical shifts are reported in parts per million (ppm) downfield from tetramethylsilane (TMS) with reference to TMS for 1 H NMR and 13 C NMR spectra. Multiplicities are abbreviated as follows: singlet (s), doublet (d), triplet (t), quartet (q), quintet (quint), sextet (sext), septet (sept), multiplet (m), and broad (br). IR spectra were collected on a Nicolet IR200 attenuated total reflectance FT-IR spectrometer and only diagnostic peaks are given. IR bands are given in cm-1 and peak intensities correspond to weak (w), medium (m), strong (s), and broad (br). High resolution mass spectrometry data were collected at the Johns Hopkins University Mass Spectrometry Facility. Analytical thin-layer chromatography (TLC) was performed using silica gel 60 F254 precoated plates (0.25 mm thickness) with a fluorescent indicator. Visualization was performed with UV light. Flash column chromatography was performed using silica gel 60 (230-400 mesh). Gas chromatograms were collected on a Thermo Scientific Trace 1300 gas chromatograph with an AI 1310 autosampler and an FID. A TR-5 (5% phenyl methylpolysiloxane) column (30 m length x 0.25 mm ID x 0.25 μm film thickness) was used under the following method conditions: 110 °C for 5 min, ramp 20 °C/min to 250 °C, hold at 250 °C for 2 min. The carrier gas was helium, used at a constant flow rate of 1 mL/min. A sample volume of 1 μL was added to the 300 °C injector at a 30:1 split ratio, and the FID temperature was 250 °C. Retention times (4.7 min for acetophenone, 4.5 min for 1-phenylethanol, 7.6 min for 4-phenyl-2-butanol, 7.4 min for 4-phenyl-2-butanone, 11.2 min for Nbenzylideneaniline, 11.5 min for N-benzylamine, and 9.0 min for biphenyl) were determined using pure samples. Synthesis of Iron Compounds Scheme S1. Synthesis of 4. (2,3,4,5-Tetraphenylcyclopentadienone)iron tricarbonyl (4). S2 A solution of 2,3,4,5tetraphenylcyclopentadienone S3 8a (3.0 g, 7.8 mmol) and iron pentacarbonyl (2.0 mL, 3.0 g, 15 mmol) in 35 mL degassed toluene in a thick-walled round-bottom flask with a PTFE screw cap was heated to 140 °C for 24 h. After cooling to rt,...

Selective molecular recognition of hydrophilic guests in water plays a fundamental role in a vast number of biological processes, but synthetic mimicry of biomolecular recognition in water still proves challenging both in terms of achieving comparable affinities and selectivities. This Review highlights strategies that have been developed in the field of supramolecular chemistry to selectively and non‐covalently bind three classes of biologically relevant molecules: nucleotides, carbohydrates, and amino acids. As several groups have systematically modified receptors for a specific guest, an evolutionary perspective is also provided in some cases. Trends in the most effective binding forces for each class are described, providing insight into selectivity and potential directions for future work.

Sensor arrays using synthetic receptors have found great utility in analyte detection, resulting from their ability to distinguish analytes based on differential signals via indicator displacement. However, synthesis and characterization of receptors for an array remain a bottleneck in the field. Receptor discovery has been streamlined using dynamic combinatorial libraries (DCLs), but the resulting receptors have primarily been utilized in isolation rather than as part of the entire library, with only a few examples that make use of the complexity of a library of receptors. Herein, we demonstrate a unique sensor array approach using "imprint-and-report" DCLs that obviates the need for receptor synthesis and isolation. This strategy leverages information stored in DCLs in the form of differential library speciation to provide a high-throughput method for both developing a sensor array and analyzing data for analyte differentiation. First, each DCL is templated with analyte to give an imprinted library, followed by in situ fluorescent indicator displacement analysis. We further demonstrate that the reverse strategy, imprinting with the fluorescent reporter followed by displacement with each analyte, provides a more sensitive method for differentiating analytes. We describe the development of this differential sensing system using the methylated Arg and Lys post-translational modifications (PTMs). Altogether, 19 combinations of 3−5 DCL data sets that discriminate all 7 PTMs were identified. Thus, a comparable sensor array workflow results in a larger payoff due to the immense information stored within multiple noncovalent networks.

Air-stable iron carbonyl compounds bearing cyclopentadienone ligands with varying substitution were explored as catalysts in dehydrogenative diol lactonization reactions using acetone as both the solvent and hydrogen acceptor. Two catalysts with trimethylsilyl groups in the 2-and 5-positions, [2,5- 2), were found to be the most active, with 2 being the most selective in the lactonization of diols containing both primary and secondary alcohols. Lactones containing five-, six-, and seven-membered rings were successfully synthesized, and no over-oxidations to carboxylic acids were detected. The lactonization of unsymmetrical diols containing two primary alcohols occurred with catalyst 1, but selectivity was low based on alcohol electronics and modest based on alcohol sterics. Evidence for a transfer dehydrogenation mechanism was found, and insight into the origin of selectivity in the lactonization of 1°/2°diols was obtained. Additionally, spectroscopic evidence for a trimethylamine-ligated iron species formed in solution during the reaction was discovered.

Widespread industrial use of per- and polyfluoroalkyl substances (PFAS) as surfactants has led to global contamination of water sources with these persistent, highly stable chemicals. As a result, humans and...