highly selective aldol fragment coupling whose stereochemical outcome is influenced by a gamma-stereogenic methyl group, and an interesting one-pot desilylation/dihydropyranone fragmentation/amidation sequence. As such, saliniketalB was obtained in 11 steps and 23% overall yield from commercially available starting material via a convergent coupling of two equally complex fragments assembled in seven
我们报告了海洋放线菌衍生的天然产物盐缩酮 B 的简洁、对映选择性和高效合成。 . 我们的策略强调了我们实验室开发的 Pt(II) 介导的炔二醇环异构化的效用,以构建二氧杂双环 [3.2.1] 辛烷环系统,这是一种高度选择性的醛醇片段偶联,其立体化学结果受伽马立体甲基的影响,以及有趣的一锅脱甲硅烷基化/二氢吡喃酮片段化/酰胺化序列。像这样,
SPIRO(5.5)UNDECANE DERIVATIVES
申请人:ZEMOLKA Saskia
公开号:US20090247505A1
公开(公告)日:2009-10-01
The invention relates to compounds that have an affinity to the μ-opioid receptor and the ORL 1-receptor, methods for their production, medications containing these compounds and the use of these compounds for the treatment of pain and other conditions.
The invention relates to compounds that have an affinity to the μ-opioid receptor and the ORL 1-receptor, methods for their production, medications containing these compounds and the use of these compounds for the treatment of pain and other conditions.
Mechanistic Investigation of the Nickel-Catalyzed Transfer Hydrocyanation of Alkynes
作者:Julia C. Reisenbauer、Patrick Finkelstein、Marc-Olivier Ebert、Bill Morandi
DOI:10.1021/acscatal.3c02977
日期:2023.9.1
cleavage step. In this work, in-depth kinetic and computationalstudies using alkynes as substrates were used to elucidate the overall reaction mechanism of this transfer hydrocyanation, with a particular focus on the activation of the C(sp3)–CN bond to generate the active H–Ni–CN transfer hydrocyanation catalyst. Comparisons of experimentally and computationally derived 13C kinetic isotope effect data support
Alkaline Earth Catalysis of Alkynyl Alcohol Hydroalkoxylation/Cyclization
作者:Christine Brinkmann、Anthony G. M. Barrett、Michael S. Hill、Panayiotis A. Procopiou、Stephanie Reid
DOI:10.1021/om3008663
日期:2012.10.22
Heavier alkaline earth bis(trimethylsilyl)amides [AeN(SiMe3)(2)}(2)](2) (Ae = Ca, Sr, Ba) are shown to act as effective precatalysts for the regioselective intramolecular hydroalkoxylation/cyclization of a wide range of alkynyl and allenyl alcohols. In the majority of cases, cyclization of alkynyl alcohols produces mixtures of the possible endo- and exocyclic enol ether products, rationalized as a consequence of alkynylalkoxide isomerization to the corresponding allene derivatives. Cyclization rates for terminal alkynyl alcohols were found to be significantly higher than for substrates bearing internal alkynyl substituents, while the efficacy of cyclization was in general found to be determined by a combination of stereoelectronic influences and the thermochemical viability of the specific alkaline earth metal catalysis, which we suggest is determined by the individual M-O bond strengths. Kinetic studies have provided a rate law pertaining to a pronounced catalyst inhibition with increasing [substrate], indicating that turnover-limiting insertion of C-C unsaturation into the M-O bond requires the dissociation of substrate molecules away from the Lewis acidic alkaline earth center.