Palladium catalyzed cyclization reactions of acetylenic lactams
作者:Willem F.J. Karstens、Marianne Stol、Floris P.J.T. Rutjes、Huub Kooijman、Anthony L. Spek、Henk Hiemstra
DOI:10.1016/s0022-328x(00)00935-9
日期:2001.4
Lactams and oxazolidinones containing a 3-butynyl side chain at the four- and the three-position, respectively, have been prepared by reductive alkylation of cyclicimides or by SN2′-substitution of bromopropadiene with highly functionalized enantiopure organozinc reagents. Treatment of these compounds with aryl halides and one vinyl bromide using Pd(PPh3)4 as a catalyst gives rise to a coupling-cyclization
内酰胺和恶唑烷酮分别在四个和三个位置上含有一个3-丁炔基侧链,是通过环酰亚胺的还原烷基化或用高度官能化的对映纯有机锌试剂对溴丙二烯进行S N 2'取代制得的。使用Pd(PPh 3)4作为催化剂,用芳基卤化物和一种乙烯基溴处理这些化合物会引起偶联环化反应,从而生成其中掺入了芳基或乙烯基部分的双环酰胺。值得注意的是,这些基团是立体选择性地顺式转移的关于氮亲核试剂到三键上。通过环化产物的晶体结构分析和NOE差光谱法已经获得了这种异常立体化学结果的结构证明。
Preparation and reactivity of chiral β-amido-alkylzinc iodides and related configurationally stable zinc organometallics
function with an acidic NH group were prepared using the direct insertion of zinc dust into the corresponding alkyl iodides in THF or THF:DMSO mixtures. Most of the starting iodides were obtained from natural α-amino acids and the resulting zinc species afforded after transmentalation with CuCN·2LiCI and reaction with a selection of relatively reactive electrophiles a variety of polyfunctional 1,2-amino
Duddu Rajagopal, Eckhardt Matthias, Furlong Michael, Knoess H. Peter, Ber+, Tetrahedron, 50 (1994) N 8, S 2415-2432
作者:Duddu Rajagopal, Eckhardt Matthias, Furlong Michael, Knoess H. Peter, Ber+
DOI:——
日期:——
Palladium-Catalysed Cyclisation of Enantiopure Allenic Lactams Prepared from a Pyroglutamic Acid Derived Organozinc Reagent
作者:Willem F. J. Karstens、Marianne Stol、Floris P. J. T. Rutjes、Henk Hiemstra
DOI:10.1055/s-1998-1859
日期:1998.10
A route for the synthesis of enantiopure allene-substituted lactams has been developed. The key-step involves the copper(I) mediated SN2′ substitution of propargylic tosylates by a (S)-pyroglutamic acid derived organozinc reagent. Pd-catalysed reaction of these allenes with iodobenzene afforded enantiopure bicyclic enamides. Furthermore the unexpected formation of an interesting diene is reported.