Photobrominations of Substituted Cumenes by <i>N</i>-Bromosuccinimide: Charge Delocalizations, Inductive Effects, and Spin Dispersions Triggered by Substituents

Photobrominations of Substituted Cumenes by N-Bromosuccinimide:  Charge Delocalizations, Inductive Effects, and Spin Dispersions Triggered by Substituent

InBr₃: A Versatile Catalyst for the Different Types of Friedel−Crafts Reactions

Mild and efficient InBr3-catalyzed Friedel−Crafts alkylation of heteroaromatic or electron-rich aromatic compounds with α-amido sulfones at room temperature in CH2Cl2 has been developed. The products undergo further Friedel−Crafts alkylation with heteroaromatic or electron-rich aromatic compounds leading to unsymmetrical or bis-symmetrical triaryl methanes in good yield. α-Amido sulfones are employed for the synthesis of the unsymmetrical and bis-symmetrical triaryl methanes. The use of mild reaction condition, low catalytic loading, and high yield are the advantages of the present procedures

Friedel−Crafts Arylation Reactions of <i>N</i>-Sulfonyl Aldimines or Sulfonamidesulfones with Electron-Rich Arenes Catalyzed by FeCl₃·6H₂O: Synthesis of Triarylmethanes and Bis-heteroarylarylmethanes

The FeCl3·6H2O-catalyzed Friedel−Crafts arylation reactions of N-sulfonyl aldimines or sulfonamidesulfones with electron-rich arenes and heteroarenes, which lead to the formation of triarylmethanes and bis-heteroarylarylmethanes, are developed. The use of mild reaction conditions, low catalytic loading, high yield, and single step synthesis are the advantages of the present procedure

Secondary α-Deuterium Kinetic Isotope Effects Signifying a Polar Transition State in the Thermolysis of Ring-Substituted <i>tert</i>-Butyl Phenylperacetates

Several ring-substituted tert-butyl phenylperacetates (YC6H4CH2CO3But) and their deuterated versions (YC6H4CD2CO3But) were prepared (Y:  p-OCH3, p-CH3, p-H, and p-NO2). Thermolyses at 80 °C in CDCl3 showed excellent first-order kinetics. The rates have been measured as kYH × 104 and kYD × 104 s-1:  11.9 and 9.20 (p-OCH3), 2.64 and 2.22 (p-CH3), 1.06 and 0.93 (p-H), 0.164 and 0.156 (p-NO2). Hammett correlations were derived to yield ρYH+ = −1.17 and ρYD+ = −1.12. However, better Hammett plots were obtained with three points (p-OCH3, p-CH3, and p-H) showing ρYH+ = −1.35 and ρYD+ = −1.28. SDKIE was calculated as 1.293 (p-OCH3), 1.189 (p-CH3), 1.140 (p-H), and 1.051 (p-NO2), showing substantial substituent effects. Values of kYH/kYD for p-NO2 showed little temperature dependence. Hammett correlations and SDKIE were derived from the same kinetic entity that is the bond cleavage

Induced Thermolysis of <i>tert</i>-Butyl Phenylperacetates by Thiophenol: Simultaneous Occurrence of Homolysis and Single Electron Transfer^†

Thermolysis of tert-butyl phenylperacetates in the presence of thiophenol takes place via dual mechanism. The two-bond homolysis indicates = −1.16, testifying to polar transition states. The single electron transfer yields a radical anion intermediate which undergoes fragmentation with ρET = 1.01

InBr₃: A Versatile Catalyst for the Different Types of Friedel−Crafts Reactions

Mild and efficient InBr3-catalyzed Friedel−Crafts alkylation of heteroaromatic or electron-rich aromatic compounds with α-amido sulfones at room temperature in CH2Cl2 has been developed. The products undergo further Friedel−Crafts alkylation with heteroaromatic or electron-rich aromatic compounds leading to unsymmetrical or bis-symmetrical triaryl methanes in good yield. α-Amido sulfones are employed for the synthesis of the unsymmetrical and bis-symmetrical triaryl methanes. The use of mild reaction condition, low catalytic loading, and high yield are the advantages of the present procedures

Thermal Isomerizations of Ketenimines to Nitriles: Evaluations of Sigma-Dot (σ^•) Constants for Spin-Delocalizations

Rate constants (kY) of the isomerizations of 11 diphenyl N-(substituted benzyl) ketenimines were measured at 40, 50, 60, and 70 °C. Activation parameters ΔH⧧Y and ΔS⧧Y were obtained using the Eyring equation. The relative rates (kY/kH) were fitted into Hammett single correlations (log kY/kH = ρσ and log kY/kH = ρ•σ•). The single correlations have been compared with Hammett dual correlations (log kY/kH = ρσ + ρ•σ• ). Separate treatments of para and meta substituents yielded even better correlations. Para substituents control the rates through spin-delocalizations and inductive effects. The former outweighs the latter when the latter exerts a modest but distinct influence on the rates. On the other hand, inductive effects are the “major” or the sole interactions triggered by meta substituents

Thermal Isomerizations of Substituted Benzyl Isocyanides: Relative Rates Controlled Entirely by Differences in Entropies of Activation^†

The absolute and relative rates of thermal rearrangments of substituted benzyl isocyanides were obtained at the temperatures between 170 and 230 °C. The relative rates are independent of temperature and exhibit excellent Hammett correlations (ρ+ = −0.24). The temperature studies yielded activation parameters ( and ) and their differential counterparts ( and ). The differential terms were plotted against σ+. The secondary α-deuterium kinetic isotope effects (kD/kH = 1.11) were measured at several temperatures. The rate data can be rationalized with the cyclic TS. The substituent effects on the rates are due to the entropic contributions

Thermolysis of <i>tert</i>-Butyl Phenylperacetates: Delicate Control of the Rates through Contributions from Translational and Rotational Entropy^†

The first-order rate constants (kY) at several temperatures in CDCl3 were measured for thermal decompositions of YC6H4CH2CO3C(CH3)3 with Y being p-OCH3, p-OPh, p-CH3, p-Ph, p-H, p-Cl, m-Cl, and p-NO2. The relative rates (kY/kH) exhibit excellent ρ+/σ+ Hammett correlations with ρ+ < 0, indicating a polar TS. Activation parameters (ΔH⧧Y and ΔS⧧Y) and their differential terms (ΔΔH⧧Y-H and ΔΔS⧧Y-H) were obtained from the Eyring plot. Differential activation terms (ΔΔH⧧Y-H and ΔΔS⧧Y-H) disclose an isokinetic relation with p-CH3, p-Ph, p-H, p-Cl, and m-Cl (isokinetic temp, 230 K). However, p-OCH3, and p-OPh show negative deviations, and a positive deviation occurs with p-NO2. Plot of ΔΔH⧧Y-H vs σ+ exhibits a good linear relation (r = 0.95) with a slope (α1 = −3.34). A better linear correlation (r = 0.97) and steeper slope (α2 = −5.22) were observed for TΔΔS⧧Y-H vs σ+. Negatively larger slope (α2 = −5.22) may point to entropy control of rates. Differential activation parameters (ΔΔH⧧Y-H and ΔΔS⧧Y-H) reflect variations of activation process. Differential activation entropies (ΔΔS⧧Y-H) are discussed in terms of contributions of translational and rotational entropies. Similar deviation behaviors of p-OCH3, p-OPh, and p-NO2 were again observed for the both plots. p-NO2 can strongly destabilize the cationic site of the polar TS but serves an eminent spin delocalizer for the homolytic TS

Additional file 1 of Association between haemoglobin A1c and all-cause and cause-specific mortality in middle-aged and older Koreans: a prospective cohort study

Additional file 1. Risk of death according to HbA1c levels at baseline or over time when further adjusted for covariates. Model 1: Adjusted for age, sex, residential area, body mass index, smoking, alcohol use, regular exercise, education, hypertension, dyslipidaemia, and RBC count. Model 2: Adjusted for age, sex, residential area, body mass index, smoking, alcohol use, regular exercise, education, hypertension, dyslipidaemia, and haemoglobin. Model 3: Adjusted for age, sex, residential area, body mass index, smoking, alcohol use, regular exercise, education, hypertension, dyslipidaemia, and anaemia. Model 4: Adjusted for age, sex, residential area, body mass index, smoking, alcohol use, regular exercise, education, hypertension, dyslipidaemia, and liver diseases. RBC red blood cell