High yield accelerated reactions in nonvolatile microthin films: chemical derivatization for analysis of single-cell intracellular fluid

Abstract

The identification of trace components from an individual cell can require derivatization under mild conditions for successful analysis by mass spectrometry (MS).

Accelerated microdroplet synthesis of benzimidazoles by nucleophilic addition to protonated carboxylic acids

“…Examples of accelerated droplet chemistry involving somewhat related mechanisms are known, in particular the acid catalyzed reaction of ketones with amines to form imines. [5][6][7][8][9][10][11][12][13] It seems likely that the extraordinarily high acidity at the surface of aqueous droplets drives these rapid reactions, even in cases like this study where the solvent is nominally non-aqueous. We explore C-N coupling of amines using protonated carboxylic acids as reagents (clearly counter-intuitive entities, given that neutral carboxylic acids are normally proton donors not acceptors).…”

“…). 11 Note that this estimate does not correct for differences in ionization energy so more accurate yields were obtained by collecting and purifying product (see below). The conversion ratios for the benzimidazole and 2-methylbenzimidazole syntheses were 27% and 3%, respectively (measured with MS inlet capillary temperature at 50 C).…”

Reaction acceleration at air‐solution interfaces: Anisotropic rate constants for Katritzky transamination

“…The effects of heat and catalysis on reaction rates are well known. More recently, enhanced reaction rates ("reaction acceleration") have been observed in confined volumes, including spraybased microdroplets, [1][2][3][4][5][6][7][8][9][10][11] thin films deposited on substrates, [12][13][14][15] emulsions, [16][17][18][19][20] merged droplets mixed instantaneously in theta tips, [21][22][23] and levitated aerosol droplets. [24][25][26][27] Based on qualitative observations regarding the short time required for reaction in charged microdroplets versus those in bulk solution, 1 a mechanism of reaction acceleration that emphasizes partial solvation at the interface has been proposed 28 although other features of the interface have also been invoked.…”

“…The effects of heat and catalysis on reaction rates are well known. More recently, enhanced reaction rates (“reaction acceleration”) have been observed in confined volumes, including spray‐based microdroplets, 1‐11 thin films deposited on substrates, 12–15 emulsions, 16–20 merged droplets mixed instantaneously in theta tips, 21–23 and levitated aerosol droplets 24–27 …”

Chemoselective N‐Alkylation of Indoles in Aqueous Microdroplets

“…Reaction rate accelerations in microdroplets have been demonstrated for carbon–carbon bond formation, carbon–nitrogen bond formation, carbon–oxygen bond formation, deprotection of N‐Boc, demetalation, and oxidation–reduction . Microdroplet synthesis has been scaled up to a production rate of about 1–30 mg min −1 , which makes it preparative . This tempting feature of microdroplet reactions also stimulates its application in many fields, such as high‐throughput reaction screening, preparation of gold nanostructures, and accelerated degradation of pharmaceuticals …”