Regio- and stereoselective ring-opening of chiral 1,3-oxazolidin-2-one derivatives by organocopper reagents provides novel access to di-, tri- and tetra-substituted alkene dipeptide isosteresElectronic supplementary information (ESI) available: synthetic procedures and characterization for 4a,b, 5a,b, 7b, 8a,b, 9a,b, 10b, 11a,b, 12b,c, 13b, 14a,b, 15, 16a,b, 17a,b, 18, 19b, 20b. See http://www.rsc.org/suppdata/p1/b2/b203482d/
作者:Shinya Oishi、Ayumu Niida、Takae Kamano、Yoshihisa Miwa、Tooru Taga、Yoshihiko Odagaki、Nobuyuki Hamanaka、Mikio Yamamoto、Keiichi Ajito、Hirokazu Tamamura、Akira Otaka、Nobutaka Fujii
DOI:10.1039/b203482d
日期:2002.7.26
Organocopper-mediated alkylation of β-(
N-Boc-2-oxo-1,3-oxazolidin-5-yl)-α,β-enoates has been intensively investigated. Alkylation proceeded regio- and stereoselectively by
anti-
SN2′ ring-opening to provide a new route to the synthesis of
ψ[(
E)-CHCH]-,
ψ[(
E)-CMeCH]- and
ψ[(
E)-CMeCMe]- type alkene dipeptide isosteres from chiral amino acid derivatives. These resulting agents are potential mimetics of type II and type II′
β-turn substructure.
有机铜介导的β-(N-Boc-2-氧代-1,3-嗯唑烷-5-基)-α,β-烯酸酯的烷基化反应已被深入研究。通过反式-SN2'环开裂,烷基化反应在区域选择性和立体选择性上进行,为从手性氨基酸衍生物合成ψ[(E)-CHCH]-、ψ[(E)-CMeCH]-和ψ[(E)-CMeCMe]-型烯丙二肽类似物提供了一条新途径。这些合成的试剂是潜在的II型和II'型β-转角结构域模拟物。
Stereoselective Synthesis of 3,6-Disubstituted-3,6-dihydropyridin-2-ones as Potential Diketopiperazine Mimetics Using Organocopper-Mediated <i>a</i><i>nti</i>-S<sub>N</sub>2‘ Reactions and Their Use in the Preparation of Low-Molecule CXCR4 Antagonists
作者:Ayumu Niida、Hiroaki Tanigaki、Eriko Inokuchi、Yoshikazu Sasaki、Shinya Oishi、Hiroaki Ohno、Hirokazu Tamamura、Zixuan Wang、Stephen C. Peiper、Kazuo Kitaura、Akira Otaka、Nobutaka Fujii
DOI:10.1021/jo060390t
日期:2006.5.1
Organocopper-mediated anti-SN2‘ reactions of γ-phosphoryloxy-α,β-unsaturated-δ-lactams were used to prepare highly functionalized diketopiperazine mimetics. The substrate phosphates 24, 32, and 47 were prepared from α-amino acid-derived allylic alcohols 10 by a sequence of reactions that included ring-closing metathesis. In the reactions of phosphates with organocopper reagents, the addition of LiCl
使用有机铜介导的γ-磷酰氧基-α,β-不饱和-δ-内酰胺的抗-S N 2'反应制备高度功能化的二酮哌嗪模拟物。基板磷酸盐24,32,和47从α氨基酸衍生的烯丙醇制备10通过反应,包括闭环复分解的序列。在磷酸盐与有机铜试剂的反应中,添加LiCl可以显着改善抗S N2'选择性,表明含有氯化锂的有机铜簇在确定区域选择性中起重要作用。该反应体系用于制备新型低分子量CXCR4-趋化因子受体拮抗剂。
Synthesis of (<i>Z</i>)-Alkene and (<i>E</i>)-Fluoroalkene-Containing Diketopiperazine Mimetics Utilizing Organocopper-Mediated Reduction−Alkylation and Diastereoselectivity Examination Using DFT Calculations
作者:Ayumu Niida、Makiko Mizumoto、Tetsuo Narumi、Eriko Inokuchi、Shinya Oishi、Hiroaki Ohno、Akira Otaka、Kazuo Kitaura、Nobutaka Fujii
DOI:10.1021/jo060202z
日期:2006.5.1
by trapping the resulting metal dienolate with an electrophile in a one-pot procedure gave α-alkylated-β,γ-unsaturated-δ-lactams in good yields. Because of side-chain steric repulsion, we found that alkylation using relatively large electrophiles such as BnBr gave mostly 3,6-trans isomers by kinetic trapping of metal enolates. On the other hand, MeI-mediated alkylations predominantly provided the unexpected
我们仔细检查了有机铜介导的γ-乙酰氧基或γ,γ-二氟-α,β-不饱和-δ-内酰胺的还原烷基化反应,以合成含(Z)-烯烃-或(E)-氟烯烃的二酮哌嗪模仿物。乙酸盐的还原2,12,14,和difluorolactam 18与高阶铜酸盐试剂(ME 3 CuLi 2·LiI·3LiBr),然后在一锅法中用亲电子试剂捕获所得的金属二烯酸酯,以良好的产率得到α-烷基化的β,γ-不饱和的δ-内酰胺。由于侧链空间排斥,我们发现使用相对较大的亲电子试剂(如BnBr)进行烷基化可通过动态捕获金属烯醇化物产生3,6-反式异构体。另一方面,尽管存在庞大的苄基侧链,但MeI介导的烷基化仍主要提供了意想不到的3,6-顺式异构体。基于密度泛函理论计算,我们得出结论,3,6-顺式异构体的形成是由于oxa-π-烯丙基锂络合物29和31的出现。