Reactions of N-chlorobenzylmethylamines with secondary amines in acetonitrile. Effect of base strength upon the imine-forming transition state

Bong-Rae Cho, Sung Keon Namgoong, Richard A. Bartsch

Research output: Contribution to journalArticle

21 Citations (Scopus)

Abstract

Reactions of N-chlorobenzylmethylamines 1 with R 2NH in MeCN have been investigated kinetically. Eliminations from 1 were quantitative and regiospecific, producing only benzylidenemethylamines. For the elimination reaction of 1 with Bu 2NH, k H/k D = 8.8, p = 0.96, ΔH‡ = 7.6 kcal/mol, and ΔS‡ = -45.1 eu were determined. The transition state structure is assessed as being highly symmetrical with similar extents of C β-H and N α-Cl bond cleavage, little carbanionic character, and significant π bond formation. The k H/k D and ρ values first increase and then decrease with enhancing amine base strength. Comparison of these results with those for related olefin-forming eliminations provides insight into the transition state differences between imine- and olefin-forming eliminations.

Original languageEnglish
Pages (from-to)1320-1324
Number of pages5
JournalJournal of Organic Chemistry
Volume51
Issue number8
Publication statusPublished - 1986 Dec 1
Externally publishedYes

Fingerprint

Imines
Alkenes
Amines
acetonitrile

ASJC Scopus subject areas

  • Organic Chemistry

Cite this

Reactions of N-chlorobenzylmethylamines with secondary amines in acetonitrile. Effect of base strength upon the imine-forming transition state. / Cho, Bong-Rae; Namgoong, Sung Keon; Bartsch, Richard A.

In: Journal of Organic Chemistry, Vol. 51, No. 8, 01.12.1986, p. 1320-1324.

Research output: Contribution to journalArticle

@article{8393238f9ffb4e69b129834e17ce0c52,
title = "Reactions of N-chlorobenzylmethylamines with secondary amines in acetonitrile. Effect of base strength upon the imine-forming transition state",
abstract = "Reactions of N-chlorobenzylmethylamines 1 with R 2NH in MeCN have been investigated kinetically. Eliminations from 1 were quantitative and regiospecific, producing only benzylidenemethylamines. For the elimination reaction of 1 with Bu 2NH, k H/k D = 8.8, p = 0.96, ΔH‡ = 7.6 kcal/mol, and ΔS‡ = -45.1 eu were determined. The transition state structure is assessed as being highly symmetrical with similar extents of C β-H and N α-Cl bond cleavage, little carbanionic character, and significant π bond formation. The k H/k D and ρ values first increase and then decrease with enhancing amine base strength. Comparison of these results with those for related olefin-forming eliminations provides insight into the transition state differences between imine- and olefin-forming eliminations.",
author = "Bong-Rae Cho and Namgoong, {Sung Keon} and Bartsch, {Richard A.}",
year = "1986",
month = "12",
day = "1",
language = "English",
volume = "51",
pages = "1320--1324",
journal = "Journal of Organic Chemistry",
issn = "0022-3263",
publisher = "American Chemical Society",
number = "8",

}

TY - JOUR

T1 - Reactions of N-chlorobenzylmethylamines with secondary amines in acetonitrile. Effect of base strength upon the imine-forming transition state

AU - Cho, Bong-Rae

AU - Namgoong, Sung Keon

AU - Bartsch, Richard A.

PY - 1986/12/1

Y1 - 1986/12/1

N2 - Reactions of N-chlorobenzylmethylamines 1 with R 2NH in MeCN have been investigated kinetically. Eliminations from 1 were quantitative and regiospecific, producing only benzylidenemethylamines. For the elimination reaction of 1 with Bu 2NH, k H/k D = 8.8, p = 0.96, ΔH‡ = 7.6 kcal/mol, and ΔS‡ = -45.1 eu were determined. The transition state structure is assessed as being highly symmetrical with similar extents of C β-H and N α-Cl bond cleavage, little carbanionic character, and significant π bond formation. The k H/k D and ρ values first increase and then decrease with enhancing amine base strength. Comparison of these results with those for related olefin-forming eliminations provides insight into the transition state differences between imine- and olefin-forming eliminations.

AB - Reactions of N-chlorobenzylmethylamines 1 with R 2NH in MeCN have been investigated kinetically. Eliminations from 1 were quantitative and regiospecific, producing only benzylidenemethylamines. For the elimination reaction of 1 with Bu 2NH, k H/k D = 8.8, p = 0.96, ΔH‡ = 7.6 kcal/mol, and ΔS‡ = -45.1 eu were determined. The transition state structure is assessed as being highly symmetrical with similar extents of C β-H and N α-Cl bond cleavage, little carbanionic character, and significant π bond formation. The k H/k D and ρ values first increase and then decrease with enhancing amine base strength. Comparison of these results with those for related olefin-forming eliminations provides insight into the transition state differences between imine- and olefin-forming eliminations.

UR - http://www.scopus.com/inward/record.url?scp=0000018091&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0000018091&partnerID=8YFLogxK

M3 - Article

VL - 51

SP - 1320

EP - 1324

JO - Journal of Organic Chemistry

JF - Journal of Organic Chemistry

SN - 0022-3263

IS - 8

ER -