Hammett 13C NMR and X-ray studies of π-allylpalladium phosphinooxazoline chiral ligand complexes

被引：13

作者：

Armstrong, PB

Bennett, LM

Constantine, RN

Fields, JL

Jasinski, JP

Staples, RJ

Bunt, RC ^{[1
]}

机构：

[1] Middlebury Coll, Dept Chem & Biochem, Middlebury, VT 05753 USA

[2] Keene State Coll, Dept Chem, Keene, NH 03435 USA

[3] Harvard Univ, Xray Crystallog Dept Chem & Chem Biol, Cambridge, MA 02138 USA

来源：

TETRAHEDRON LETTERS | 2005年 / 46卷 / 09期

关键词：

asymmetric catalysis; Hammett analysis; N; P-ligands; palladium; pi-allyl complexes;

D O I：

10.1016/j.tetlet.2005.01.032

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

The transmission of substituent effects across the palladium center to the allyl carbons is monitored by C-13 NMR and X-ray crystallography as a way to probe electronic asymmetry in chiral ligand design. Based on their similar chemical shift trends and X-ray structures, the pi-allylpalladium intermediates provide a good model for early transition state reactions, which are less sensitive to electronic perturbations. Hammett analysis supports an electronic basis for enantioselection that increases as the transition state becomes later. (C) 2005 Elsevier Ltd. All rights reserved.

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收藏

页码：1441 / 1445

页数：5

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