Using symmetry to monitor geared bond rotation in aromatic amides by dynamic NMR

被引：28

作者：

Bragg, RA ^{[1
]}

Clayden, J ^{[1
]}

机构：

[1] Univ Manchester, Dept Chem, Manchester M13 9PL, Lancs, England

来源：

ORGANIC LETTERS | 2000年 / 2卷 / 21期

关键词：

D O I：

10.1021/ol0064462

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

[GRAPHICS] Dynamic NMR proves that the fastest interconversion between conformers of simple tertiary aromatic amide 3 is racemization via a geared (correlated) rotation of both the Ar-CO and N-CO bonds. The symmetry of 3 is such that correlated and noncorrelated rotations are easily distinguishable, even without assignment of the NMR spectrum, simply by observing the number of peaks taking part in the exchange.

引用

页码：3351 / 3354

页数：4

共 15 条

[1] Barriers to rotation about the chiral axis of tertiary aromatic amides [J].

Ahmed, A ;

Bragg, RA ;

Clayden, J ;

Lai, LW ;

McCarthy, C ;

Pink, JH ;

Westlund, N ;

Yasin, SA .

TETRAHEDRON, 1998, 54 (43) :13277-13294

[2] TOTAL ASYMMETRIC TRANSFORMATION OF AN N-METHYLBENZAMIDE [J].

AZUMAYA, I ;

YAMAGUCHI, K ;

OKAMOTO, I ;

KAGECHIKA, H ;

SHUDO, K .

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1995, 117 (35) :9083-9084

[3]

BERG U, 1979, NOUV J CHIM, V3, P175

[4] Diastereoselective ortholithiation and conformational control in stereospecific dearomatising anionic cyclisations [J].

Bragg, RA ;

Clayden, J .

TETRAHEDRON LETTERS, 1999, 40 (48) :8327-8331

[5]

Clayden J, 1998, ANGEW CHEM INT EDIT, V37, P1937, DOI 10.1002/(SICI)1521-3773(19980803)37:13/14<1937::AID-ANIE1937>3.0.CO

[6]

2-4

[7] The first synthesis of an optically active molecular bevel gear with only two cogs on each wheel [J].

Fuji, K ;

Oka, T ;

Kawabata, T ;

Kinoshita, T .

TETRAHEDRON LETTERS, 1998, 39 (11) :1373-1376

[8] STEREOCHEMICAL CONSEQUENCES OF DYNAMIC GEARING [J].

IWAMURA, H ;

MISLOW, K .

ACCOUNTS OF CHEMICAL RESEARCH, 1988, 21 (04) :175-182

[9] Axially chiral thioamides of acrylic acid: correlated and uncorrelated internal rotations [J].

Kuttenberger, M ;

Frieser, M ;

Hofweber, M ;

Mannschreck, A .

TETRAHEDRON-ASYMMETRY, 1998, 9 (20) :3629-3645

[10] Z,E isomerism and hindered rotations in malonamides:: an NMR study of N,N′-dimethyl-N,N′-dibutyl-2-tetradecylpropane-1,3-diamide [J].

Lefrançois, L ;

Hébrant, M ;

Tondre, C ;

Delpuech, JJ ;

Berthon, C ;

Madic, C .

JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 2, 1999, (06) :1149-1158

← 1 2 →