Synthesis of azetidines by electrophilic selenium-induced cyclization of homoallylic benzylamines
摘要:
Homoallyl benzylamines, prepared by allylation of the corresponding N-benzylimines, have been subjected to a selenium-induced cyclization under various conditions. At room temperature, the 4-exo and the 5-endo modes are competitive. In acetonitrile, the azetidine has been isolated as the major cyclization product, especially for homoallylamines derived from ketimines. With an excess of selenium reagent, 3-halopyrrolidines have been obtained. (C) 1997 Published by Elsevier Science Ltd.
Novel and Efficient Method for the Allylation of Carbonyl Compounds and Imines Using Triallylaluminum
作者:Kao-Hsien Shen、Ching-Fa Yao
DOI:10.1021/jo052385f
日期:2006.5.1
triallylaluminum as a reagent for the allylation of carbonyl compounds and imines. The allylation of ketimines without additional metal catalyst is known so far only in the case of the Grignardreagent. Triallylaluminum is a useful alternative to provide the homoallylic amines in excellent yield upon addition to aldimines and ketimines. The significant reactivity of this reagent was confirmed by its
“Barbier Type” allylation of imines with allylbromide has been performed successfully by the action of aluminum (1 equiv.) and titanium(IV)chloride (0.05 equiv.) in THF. The chirality transfer of α-amino acid esters to homoallyl amines is demonstrated by allylation of N-benzalvaline methyl ester followed by alkaline hydrolysis and electrolytic decarboxylation.
Mg and Zn mediated allylation of imines with allyl bromide
作者:De-Kun Wang、Li-Xin Dai、Xue-Long Hou、Yi Zhang
DOI:10.1016/0040-4039(96)00791-5
日期:1996.6
Both aldimines and ketimines are allylated under simple Barbier-type conditions using allylbromide and commercial magnesium foil or zinc dust in tetrahydrofuran at room temperature.
Preparation and Reactions of Masked Allylic Organozinc Reagents
作者:Philip Jones、Paul Knochel
DOI:10.1021/jo981623m
日期:1999.1.1
Allyliczinc reagents have been prepared from sterically hindered homoallylic alcohols 10 and 13, using a novel fragmentation reaction of the corresponding zinc alkoxide, without any homocoupling products. These allyliczinc reagents react with a range of electrophiles in good to excellent yields. Substitutedallyliczinc reagents have also been prepared in this manner. alpha-Substituted homoallylic