合成了一系列新的30种对称双吡啶鎓和相关的N-杂芳族双季铵盐与丙烷-1,3-二基连接基,并表征了它们在加利福尼亚鱼雷的烟碱乙酰胆碱受体(nAChR)MB327结合位点的结合亲和力。靶向此结合位点的化合物对于研究针对有机磷酸酯中毒的新型解毒剂特别感兴趣,因为其具有治疗活性,可被4-叔丁基取代的双吡啶鎓盐MB327以前被鉴定为nAChR再敏化剂。通过新开发的方法可以有效地获得目标化合物,该方法可以使具有多种官能团的空间受阻或电子失活的杂环进行N烷基化。使用最近开发的基于质谱(MS)的结合测定法测定对nAChR处MB327结合位点的结合亲和力,结果表明几种化合物的亲和力与MB327相似(p K i = 4.73±0.03)。值得注意的是,发现新制备的亲脂性4-叔丁基-3-苯基取代的双吡啶鎓盐PTM0022(3 h)具有明显更高的结合亲和力,p Ki值为5.16±0.07,代表在开发更有效的nAChR再敏化剂方面取得了可观的进步。
Catalyticasymmetric protonation of chiral calcium enolates was performed. Chiral calcium enolates, prepared in situ from imides and malonates via 1,4-addition in the presence of catalytic amounts of Ca(OEt)(2), Ph-PyBox, and achiral phenol, were smoothly protonated to afford adducts bearing tertiary asymmetric carbons in high yields with high enantioselectivities. The adducts were readily converted
Metal-Catalyzed Rearrangement of Homoallylic Ethers to Silylmethyl Allylic Silanes in the Presence of a Di-<i>tert</i>-butylsilylene Source
作者:Pamela A. Cleary、K. A. Woerpel
DOI:10.1021/ol052456x
日期:2005.11.1
transfer to gem-disubstituted alkenes to form silacyclopropanes, we discovered an unprecedented reaction of homoallylic ethers. When silylene transfer was performed at room temperature or above, two di-tert-butylsilylene units were incorporated into the molecule, and complete rearrangement of the carbon backbone occurred. This report describes the scope of this unique reaction as well as the mechanistic
Isocyano Enones: Addition–Cyclization Cascade to Oxazoles
作者:Allen Chao、J. Armando Lujan-Montelongo、Fraser F. Fleming
DOI:10.1021/acs.orglett.6b01147
日期:2016.7.1
Copper iodide catalyzes the conjugate addition of organometallic and heteroatom nucleophiles to isocyano enones to afford oxazoles. A range of enolates, metalated nitriles, amines, and thiols undergo catalyzed conjugate addition to cyclic and acyclic oxoalkene isocyanides. Mechanistic studies suggest that copper complexation facilitates the nucleophilic attack on the isocyano enone to generate an enolate
Deprotonation of hydrazinium dications in the diazoniapropellane series to form bridgehead iminium ions; external and intramolecular trapping
作者:Roger W. Alder、Richard B. Sessions、John O. Gmünder、Cyril A. Grob
DOI:10.1039/p29840000411
日期:——
amino group or externally by addednucleophiles. Reaction with cyanide ion gives detailed information on the regio- and stereo-chemistry of the trapping sequence. Although intramolecular/external trapping is truly competitive, the products of these reactions (α-amino-ammonium ions and α-aminonitriles) may be interconverted under different reaction conditions. The solvolysis of 1-(3-phenoxypropyl)-1,5-diazabicyclo[3
描述了六烷基肼基阳离子与碱和亲核试剂的反应。1,N-三唑[3.3.2.0]癸烷(1)通过S N 2攻击具有开环(C + +裂解)的四元环而迅速水解。在所有其他情况下,在α–C处伴随N + –N +裂解(E 2反应)的去质子化是唯一的主要过程。该顺-1,6-二甲基-1,6-二氮杂双环[4.4.0]癸烷离子(6)仅在甲基(霍夫曼方向)上去质子化。1,5-二氮杂三环[3.3.3.0]-十一烷(2),1、6-二氮杂三环[4.3.3.0]十二烷(3),1、6--二氮杂三环[4.4.3.0]十三烷(4)和1,6 -二氮杂三环[4.4.4.0]十四烷(5)离子产生桥头亚胺离子,该离子可能在分子内被跨环氨基捕获,或在外部被附加的亲核试剂捕获。与氰化物离子的反应给出了有关捕获序列的区域和立体化学的详细信息。尽管分子内/外部捕集确实具有竞争优势,但这些反应的产物(α-氨基铵离子和α-氨基腈)可以在不同的反应条
Catalytic Mannich-Type Reactions of Sulfonylimidates
作者:Ryosuke Matsubara、Florian Berthiol、Huy V. Nguyen、Shu Kobayashi
DOI:10.1246/bcsj.82.1083
日期:2009.9.15
case of Ts-imidate. Alkali earth metal alkoxide and its HMDS salt also catalyze Mannich-type reactions of sulfonylimidates. The reactionscatalyzed by Mg(O t Bu) 2 in DMF provided the adducts with high anti selectivity, while those catalyzed by [Sr(HMDS) 2 ] 2 gave syn selectivity. The asymmetric variant of Mannich-type reaction of sulfonylimidate was also achieved. Several transformations of sulfonylimidates