[formula: see text] Catalytic acylation using complex transition metal salts MCo(CO)4 is demonstrated. Surprisingly, a solvent-dependent mechanistic "switch" results in a Lewis acid-based acylation mechanism in nonpolar media and a nucleophilic mechanism in polar organic media. These observations lead to the first example of a catalyzed Staudinger reaction to form beta-lactams.

Several Zn b-diiminate reagents were developed and used to mediate regioselective O-acylation reactions of therapeutic agents with anhydrides. Various prodrugs were obtained in excellent yield and high regioselectivity, including derivatives of rapamycin and paclitaxel. Furthermore, the application of regioselective acylation was extended to one-pot reactions between therapeutics and carboxylic...

Post-translational modification of lysine residues by NƐ-acylation is an important regulator of protein function. Many large-scale protein acylation studies have assessed relative changes of lysine acylation sites after antibody enrichment using mass spectrometry-based proteomics. Although relative acylation fold-changes are important, this does not reveal site occupancy, or stoichiometry, of i...

Simple catalysts that use atom-economical oxygen as the terminal oxidant to accomplish selective ortho-ortho, ortho-para, or para-para homo-couplings of phenols are described. In addition, chromium salen catalysts have been discovered as uniquely effective in the cross-coupling of different phenols with high chemo- and regioselectivity.

Installing subsurface tile drain systems in poorly drained claypan soils to improve corn ( L.) yields could potentially increase environmental phosphorus (P) loss through the tile drainage system. The objectives of the study were to quantify the average concentration and loss of ortho-P in tile drain water from a claypan soil and to determine whether managed subsurface drainage (MD) could reduc...

Nitration of N-acetyl anilides using a simple combination AgNO3 and K2S2O8 as stable nitro source an oxidant, respectively, was explored. The reaction practical to operate proceeded under considerably mild conditions (reflux in acetonitrile) within acceptable time (6 h). para-substituted gave only ortho-nitrated products moderate good yields (30–63% yields). ortho-, meta-, or non-substituted mi...

PURPOSE This single-masked randomized clinical trial aimed to evaluate the effectiveness of orthokeratology (ortho-k) for myopic control. METHODS A total of 102 eligible subjects, ranging in age from 6 to 10 years, with myopia between 0.50 and 4.00 diopters (D) and astigmatism not more than 1.25D, were randomly assigned to wear ortho-k lenses or single-vision glasses for a period of 2 years. ...

A range of N-protected-alpha-amino acyl-5,7-dinitroindolines 3a-z were prepared in good yields from commercially available N-protected-alpha-amino acids 1a-z by a two-step sequence of acylation and intramolecular amide N-arylation. Subsequent photochemical acylation of the N-protected-alpha-amino acyl-5,7-dinitroindolines 3e,g,r afforded the corresponding N-protected-alpha-amino acid amides 22e...

The smallest histone deacetylase (HDAC) and the only class IV HDAC member, HDAC11, is reported to regulate immune activation and tumorigenesis, yet its physiological function is largely unknown. Here we identify HDAC11 as an efficient lysine defatty-acylase that is >10,000-fold more efficient than its deacetylase activity. Through proteomics studies, we identified SHMT2 as a defatty-acylation s...

The ortho-nitro effect was discovered in sulfa-Staudinger cycloadditions of ethoxycarbonylsulfene with linear imines. When an ortho-nitro group is present at the C-aryl substituents of linear imines, the sulfa-Staudinger cycloadditions deliver cis-β-sultams in considerable amounts, together with the predominant trans-β-sultams. In other cases, the above sulfa-Staudinger cycloadditions give rise...