The activation barrier to axial torsion in 2,2'-bis(diphenylphosphino)biphenyl

被引：58

作者：

Desponds, O ^{[1
]}

Schlosser, M ^{[1
]}

机构：

[1] UNIV LAUSANNE,INST CHIM ORGAN,CH-1015 LAUSANNE,SWITZERLAND

来源：

TETRAHEDRON LETTERS | 1996年 / 37卷 / 01期

关键词：

D O I：

10.1016/0040-4039(95)02080-2

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

After selective deuteriation of 2,2'-bis(diphenylphosphino)biphenyl, it was possible to determine the nmr coalescence temperature of the diastereotopic phenyl groups. On this basis, a torsional barrier of 22 kcal/mol was calculated. Thus, the bisphosphine, even if it could be resolved into pure cnantiomers, would rapidly reracemize at temperatures around or above 25 degrees C.

引用

页码：47 / 48

页数：2

共 8 条

[1]

DESPONDS O, 1995, IN PRESS J ORGANOMET

[2]

Garnet J. L., 1967, J CHEM SOC CHEM COMM, P1001

[3]

GUNTHER H, 1983, NMR SPECTROSKOPIE, P226

[4]

GUNTHER H, 1973, NMR SPECTROSCOPY, P240

[5] EFFICIENT SYNTHESIS OF (R)-(6,6'-DIFLUOROBIPHENYL-2,2'-DIYL)BIS(DIPHENYLPHOSPHINE) AND (S)-(6,6'-DIFLUOROBIPHENYL-2,2'-DIYL)BIS(DIPHENYLPHOSPHINE) - ELECTRON-POOR BIPHENYL-TYPE LIGANDS FOR TRANSITION-METAL CATALYSTS [J].

JENDRALLA, H ;

LI, CH ;

PAULUS, E .

TETRAHEDRON-ASYMMETRY, 1994, 5 (07) :1297-1320

[6]

MARTIN ML, 1980, PRACTICAL NMR SPECTR, P299

[7]

MIYAMOTO TK, 1989, J ORGANOMET CHEM, V373, pC8

[8]

UEHARA A, 1982, J ORG CHEM, V239, pC11

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