Lithiation of 2-heterosubstituted pyridines with BuLi-LiDMAE: Evidence for regiospecificity at C-6

被引：41

作者：

Gros, P ^{[1
]}

Choppin, S ^{[1
]}

Mathieu, J ^{[1
]}

Fort, Y ^{[1
]}

机构：

[1] Univ Nancy 1, Fac Sci, CNRS UHP, UMR 7565, F-54506 Vandoeuvre Les Nancy, France

来源：

JOURNAL OF ORGANIC CHEMISTRY | 2002年 / 67卷 / 01期

关键词：

D O I：

10.1021/jo015855o

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

The determination of the initial deprotonation site of 2-chloro- and 2-methoxypyridine during reaction with BuLi-LiDMAE has been investigated. A series of experiments on deuterated regioisomers revealed a direct lithiation at C-6 excluding a potential first classical ortholithiation and lithium equilibration in the reaction medium. These results suggested that the formation of lithium aggregates at the neighboring of the pyridinic nitrogen atom favored BuLi delivery at C-6 as well as 6-lithio intermediate stabilization.

引用

页码：234 / 237

页数：4

共 27 条

[1] Anion translocation in organolithiums: A mechanism for the lithiation and cyclisation of tertiary naphthamides [J].

Ahmed, A ;

Clayden, J ;

Rowley, M .

TETRAHEDRON LETTERS, 1998, 39 (34) :6103-6106

[2] Complex-induced proximity effects in directed lithiations: Analysis of intra- and intermolecular kinetic isotope effects in directed aryl and benzylic lithiations [J].

Anderson, DR ;

Faibish, NC ;

Beak, P .

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1999, 121 (33) :7553-7558

[3] STEREOCONTROL AND REGIOCONTROL BY COMPLEX INDUCED PROXIMITY EFFECTS - REACTIONS OF ORGANOLITHIUM COMPOUNDS [J].

BEAK, P ;

MEYERS, AI .

ACCOUNTS OF CHEMICAL RESEARCH, 1986, 19 (11) :356-363

[4] UNIMETAL SUPER BASES [J].

CAUBERE, P .

CHEMICAL REVIEWS, 1993, 93 (06) :2317-2334

[5] Are n-BuLi/TMEDA-mediated arene ortholithiations directed?: Substituent-dependent rates, substituent-independent mechanisms [J].

Chadwick, ST ;

Rennels, RA ;

Rutherford, JL ;

Collum, DB .

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 2000, 122 (36) :8640-8647

[6]

Choppin S, 2001, EUR J ORG CHEM, V2001, P603, DOI 10.1002/1099-0690(200102)2001:3<603::AID-EJOC603>3.0.CO

[7]

2-2

[8] Unusual C-6 lithiation of 2-chloropyridine-mediated by BuLi-Me2N(CH2)2OLi.: New access to 6-functional-2-chloropyridines and chloro-bis-heterocycles [J].

Choppin, S ;

Gros, P ;

Fort, Y .

ORGANIC LETTERS, 2000, 2 (06) :803-805

[9] A 10-STEP, ASYMMETRIC-SYNTHESIS OF (S)-CAMPTOTHECIN [J].

COMINS, DL ;

BAEVSKY, MF ;

HONG, H .

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1992, 114 (27) :10971-10972

[10] ORTHO LITHIATION OF 2-METHOXYPYRIDINES, 3-METHOXYPYRIDINES, AND 4-METHOXYPYRIDINES [J].

COMINS, DL ;

LAMUNYON, DH .

TETRAHEDRON LETTERS, 1988, 29 (07) :773-776

← 1 2 3 →