Cyclization or hydrogen migration: Theoretical study and experimental evidence on the reactivities of unsaturated amidyl radicals

被引：36

作者：

Chen, Q ^{[1
]}

Shen, MH ^{[1
]}

Tang, Y ^{[1
]}

Li, CZ ^{[1
]}

机构：

[1] Chinese Acad Sci, Shanghai Inst Organ Chem, Shanghai 200032, Peoples R China

来源：

ORGANIC LETTERS | 2005年 / 7卷 / 08期

关键词：

D O I：

10.1021/ol050437h

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

Theoretical calculations (B3LYP/6-31G*) backed up by deuterated experiments reveal that the N-substituents (R) play a crucial role in determining the reaction pathways of unsaturated amidyl radicals. With the increase of the bulkiness of N-alkyl group, the activation energy for 6-exo cyclization increases steadily, while the activation energy for 1,5-H abstraction remains almost unchanged. Therefore, cyclization occurs exclusively when R is H while 1,5-H migration occurs exclusively when R is t-Bu.

引用

页码：1625 / 1627

页数：3

共 25 条

[1] PHOTOCHEMICAL TRANSFORMATIONS .16. A NOVEL SYNTHESIS OF LACTONES [J].

BARTON, DHR ;

BECKWITH, AL ;

GOOSEN, A .

JOURNAL OF THE CHEMICAL SOCIETY, 1965, (JAN) :181-&

[2] Design of radical-resistant amino acid residues: A combined theoretical and experimental investigation [J].

Croft, AK ;

Easton, CJ ;

Radom, L .

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 2003, 125 (14) :4119-4124

[3] Axial and equatorial cyclohexylacyl and tetrahydropyranyl-2-acyl radicals. An experimental and theoretical study [J].

DiLabio, GA ;

Ingold, KU ;

Roydhouse, MD ;

Walton, JC .

ORGANIC LETTERS, 2004, 6 (23) :4319-4322

[4] TRANSITION-STATE MODELING WITH EMPIRICAL FORCE-FIELDS [J].

EKSTEROWICZ, JE ;

HOUK, KN .

CHEMICAL REVIEWS, 1993, 93 (07) :2439-2461

[5] THE GENERATION OF NITROGEN RADICALS AND THEIR CYCLIZATIONS FOR THE CONSTRUCTION OF THE PYRROLIDINE NUCLEUS [J].

ESKER, JL ;

NEWCOMB, M .

ADVANCES IN HETEROCYCLIC CHEMISTRY, VOL 58, 1993, 58 :1-45

[6] AMIDYL RADICALS FROM N-(PHENYLTHIO)AMIDES [J].

ESKER, JL ;

NEWCOMB, M .

TETRAHEDRON LETTERS, 1993, 34 (43) :6877-6880

[7] Free radical cyclizations involving nitrogen [J].

Fallis, AG ;

Brinza, IM .

TETRAHEDRON, 1997, 53 (52) :17543-17594

[8] 5-azahexenoyl radicals cyclize via nucleophilic addition to the acyl carbon rather than 5-exo homolytic addition at the imine [J].

Falzon, CT ;

Ryu, I ;

Schiesser, CH .

CHEMICAL COMMUNICATIONS, 2002, (20) :2338-2339

[9]

Frisch M., 2016, Gaussian, V16

[10]

GAGOSZ F, 2004, ORG LETT, V6, P3229

← 1 2 3 →