Kinetic Studies of Bimolecular Nucleophilic Substitution. VII. The Rates of the Menschutkin Reaction of Methyl Iodide with Various Primary, Secondary and Tertiary Amines in Benzene Solvent

Abstract

The nucleophilicity of a series of primary, secondary and tertiary amines, i. e., methyl-amines, ethylamines, n-butylamines, ethanolamines and benzylamines, has been investigated by following the kinetics of the reaction of these amines with methyl iodide in benzene solvent. The effect of substituents attached to nitrogen atom on the nucleophilicity of these amines is interpreted in terms of the antagonism between steric retardation and inductive effect. The low nucleophilicity observed in the case of tertiary amines is ascribed to the steric retardation at the expense of the inductive acceleration by the substituents. No linear correlation of the nucleophilicity of amines with the pKa values has been observed.

Synthesis of γ-substituted carbonyl compounds from DMSO-mediated oxidation of enynamides: mechanistic insights and carbon- and hetero-functionalizations

“…15 From the Eyring equation, the activation parameters were determined to be Δ H ‡ = 83.5 kJ mol –1 and Δ S ‡ = –37.6 J K –1 mol –1 . The large negative entropy of activation is consistent with an associative transition state, such as TS 19–22 24. Other associative steps, such as protonation of the enynamides ( 4b to 18 ) or addition of DMSO ( 18 to 19 ) were excluded, because if these earlier steps were turnover-limiting, different sensitivity ( ρ ) depending on the nucleophiles (Scheme 2) should not have been observed.…”

Structural Modifications to Quaternary Ammonium Polymer Coagulants to Inhibit N-Nitrosamine Formation

“…Methyl iodide (MeI), which undergoes the Menschutkin reaction , with primary, secondary, and tertiary amines, , was chosen as the alkylating agent for treatment of polyDADMAC or Epi-DMA following a three-step protocol. First, a Pyrex vial was charged with an aliquot of either polyDADMAC or Epi-DMA stock solutions received from the water utilities and dried in a vacuum oven at 75 °C until constant mass.…”

“…Second, a Pyrex vial was charged with 9.5 mL of freshly distilled allyldipropylamine and 30 mL of acetone. To the resulting solution was added, all at once via a glass syringe, 4.5 mL of allyl chloride, and the mixture was left to stand at 23 heating block for 24 h. The solidified polymer gel, polyDADPAC, was redissolved in 10 mL of methanol and reprecipitated with 100 mL of 9:1 (v/v) acetone:absolute ethanol. After decanting the supernatant, the polymer was recovered by vacuum evaporation of solvents, yielding 1.9 g of a light-yellow solid.…”