描述了2-羟基肟醚的第一Sc(OTf)3催化脱水以生成苄基稳定的1-氮杂烯丙基阳离子,其被1,3-羰基捕获。随后在顺序的三组分反应中添加伯胺可提供高取代度和高密度官能化的四氢茚并[2,1- b ]吡咯作为单一非对映异构体,并具有最高的定量收率。因此,在一锅操作中生成了三个新的σ键和两个相邻的四元立体生成中心。
Enolate-Based Regioselective Anti-Beckmann C–C Bond Cleavage of Ketones
作者:Tomáš Mašek、Ullrich Jahn
DOI:10.1021/acs.joc.1c01169
日期:2021.9.3
provides a direct and regioselective way of fragmenting ketones into esters and oximes or ω-hydroxyimino esters, respectively. A comprehensive study of the scope of this reaction with respect to ketone classes and alkyl nitrites is presented. Control over the site of cleavage is gained through regioselective enolate formation by various bases. Oxidation of kinetic enolates of unsymmetrical ketones leads to
Synthesis and antiinflammatory activity of trisubstituted pyrimidines and triazines
作者:Gregory B. Bennett、Robert B. Mason、Lee J. Alden、James B. Roach
DOI:10.1021/jm00205a006
日期:1978.7
A series of mono-, bi-, and tricyclic pyrimidines and as-triazines was prepared and their antiinflammatory activity measured against carrageenan-induced edema in the rat. The more active analogues (ED50), including 4-pyri-dylpyrimidines 4a (38), 4b (47), and 4g (49) and 2-hydroxypyrimidine 8r (43), were then tested against adjuvant-induced edema in the rat. None was active in the adjuvant arthritis
An efficient and simple source of nitroso reagents and their oxidation reactions are described. The combination of a Lewis acid and a metal nitrite was applied to the oxidation of silyl enol ethers. Amino acid and peptide derivatives were easily accessed through in situ C-C bond cleavage of fully substituted silyl enol ethers upon oxidation.
描述了亚硝基试剂及其氧化反应的有效且简单的来源。路易斯酸和金属亚硝酸盐的组合应用于甲硅烷基烯醇醚的氧化。通过氧化时完全取代的甲硅烷基烯醇醚的原位 CC 键裂解,可以很容易地获得氨基酸和肽衍生物。
<i>trans</i>-Diastereoselective Ru(II)-Catalyzed Asymmetric Transfer Hydrogenation of α-Acetamido Benzocyclic Ketones via Dynamic Kinetic Resolution
A highly efficient enantio- and diastereoselective catalyzed asymmetrictransferhydrogenation via dynamic kinetic resolution (DKR–ATH) of α,β-dehydro-α-acetamido and α-acetamido benzocyclic ketones to ent-trans-β-amido alcohols is disclosed employing a new ansa-Ru(II) complex of an enantiomericallypure syn-N,N-ligand, i.e. ent-syn-ULTAM-(CH2)3Ph. DFT calculations of the transition state structures
Synthesis of Acyl Fluorides via DAST-Mediated Fluorinative C–C Bond Cleavage of Activated Ketones
作者:Danhee Kim、Hee Nam Lim
DOI:10.1021/acs.orglett.0c02603
日期:2020.10.2
scope compared with previously reported methods that employ carboxylic acids as substrates. A working hypothesis of pull-and-push-driven fluorinative C–C bond cleavage was successfully demonstrated by the simple addition of diethylaminosulfurtrifluoride (DAST) derivatives to α-oximinoketones. The designed reaction system led to a highly efficient and chemoselective reaction. The wide availability of the