Regiospecific synthesis of 5-silyl azoles

被引:56
作者
Cuadrado, P [1 ]
González-Nogal, AM [1 ]
Valero, R [1 ]
机构
[1] Univ Valladolid, Dept Quim Organ, E-47011 Valladolid, Spain
关键词
5-silyl azoles; condensation; electrophiles;
D O I
10.1016/S0040-4020(02)00386-1
中图分类号
O62 [有机化学];
学科分类号
070303 ; 081704 ;
摘要
5-Silylisoxazoles bearing other silyl groups different to the more usual trimethylsilyl have been prepared by condensation of silylalkynones with hydroxylamine hydrochloride. The reaction with hydrazines is more complex and leads to 5-silylpyrazoles or the corresponding hydrazones, which can be cyclized by reaction with electrophiles. This has allowed us to synthesize 5-silylpyrazoles functionalized at C-4 by groups impossible to introduce by electrophilic substitution of the pyrazole nucleus. (C) 2002 Elsevier Science Ltd. All rights reserved.
引用
收藏
页码:4975 / 4980
页数:6
相关论文
共 9 条
[1]   SYNTHESIS OF VINYLSILANES BY SILYL-CUPRATION OF ACETYLENES USING TERT-BUTYLDIPHENYLSILYL-CUPRATE REAGENTS [J].
BARBERO, A ;
CUADRADO, P ;
FLEMING, I ;
GONZALEZ, AM ;
PULIDO, FJ ;
SANCHEZ, A .
JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 1, 1995, (12) :1525-1532
[2]   SILYL DERIVATIVES OF PYRAZOLE, ISOXAZOLE AND 1,2,3-TRIAZOLE [J].
BIRKOFER, L ;
RICHTZENHAIN, K .
CHEMISCHE BERICHTE-RECUEIL, 1979, 112 (08) :2829-2836
[3]  
Calle M, 2001, SYNTHESIS-STUTTGART, P1949
[4]   Synthesis of silylated β-enaminones and applications to the synthesis of silyl heterocycles [J].
Calvo, LA ;
González-Nogal, AM ;
González-Ortega, A ;
Sañudo, MC .
TETRAHEDRON LETTERS, 2001, 42 (51) :8981-8984
[5]  
CHAN TH, 1979, SYNTHESIS-STUTTGART, P775
[6]   GEMINAL-DEHALOSILYLATION OF ALPHA-HALO-BETA,BETA-DIMETHYLVINYLTRIMETHYLSILANES - GENERATION OF ISOPROPYLIDENE CARBENE [J].
CUNICO, RF ;
HAN, YK .
JOURNAL OF ORGANOMETALLIC CHEMISTRY, 1978, 162 (01) :1-16
[7]   ELECTROPHILIC AROMATIC-SUBSTITUTION .26. REGIOSELECTIVE HALODESILYLATION AND CARBODESILYLATION OF (TRIMETHYLSILYL)-1-METHYLPYRAZOLES [J].
EFFENBERGER, F ;
KREBS, A .
JOURNAL OF ORGANIC CHEMISTRY, 1984, 49 (24) :4687-4695
[8]  
Fleming I., 1989, ORG REACTIONS, V37, P57
[9]  
HOPPE I, 1979, LIEBIGS ANN CHEM, P219