Yb(<scp>iii</scp>)-catalysed <i>syn</i>-thioallylation of ynamides
作者:Manash Protim Gogoi、Rajeshwer Vanjari、B. Prabagar、Shengwen Yang、Shubham Dutta、Rajendra K. Mallick、Vincent Gandon、Akhila K. Sahoo
DOI:10.1039/d1cc02611a
日期:——
incorporating a sulfide moiety at the α-position and an allyl group at the β-position of the ynamide. The transformation is successful under ytterbium(III)-catalysis, providing access to highly substituted thioamino-skipped-dienes with broad substrate scope. Thus, tetrasubstituted olefins (with four different functionalgroups: amide, phenyl, thioaryl/alkyl, and allyl on the carbon centers) are made in a single
本文报道的是一种顺式结合在α位的烯丙基在炔酰胺的β位的硫化物部分和ynamides的-thioallylation。该转化在镱 ( III ) 催化下成功,提供了获得具有广泛底物范围的高度取代的硫氨基跳过二烯的途径。因此,四取代的烯烃(在碳中心上具有四个不同的官能团:酰胺、苯基、硫代芳基/烷基和烯丙基)是由易于获得的 ynamides 一步制成的,从而保持完整的原子经济性。该反应可扩展到由炔酰胺合成selenoamino二烯的顺式-selenoallylation。DFT 研究和控制实验提供了对反应机制的深入了解。
Difluoroacetaldehyde
<i>N</i>
‐Triftosylhydrazone (DFHZ‐Tfs) as a Bench‐Stable Crystalline Diazo Surrogate for Diazoacetaldehyde and Difluorodiazoethane
study, we developed a bench-stable difluoroacetaldehyde N-triftosylhydrazone (DFHZ-Tfs) as an operationally safe diazo surrogate that can release in situ two low-molecular-weight diazoalkanes, diazoacetaldehyde (CHOCHN2 ) or difluorodiazoethane (CF2 HCHN2 ), in a controlled fashion under specific conditions. DFHZ-Tfs has been successfully employed in the Fe-catalyzed cyclopropanation and Doyle-Kirmse
Zinc Bismuthate Zn(BiO<sub>3</sub>)<sub>2</sub>. I. A Useful Oxidizing Agent for the Efficient Oxidation of Organic Compounds
作者:Habib Firouzabadi、Iraj Mohammadpour-Baltork
DOI:10.1246/bcsj.65.1131
日期:1992.4
Zinc bismuthate is an easily prepared and a stable compound. It could be used as an oxidant in organic solvents under aprotic or in the presence of a catalytic amount of a protic solvent. Primary a...
pyrazoleamides and a chiral N, N'-dioxide-nickel(II) complex catalyst enables a highly enantioselective Doyle-Kirmse reaction. The pyrazoleamide substituent serves as both an activating and a directing group for the ready formation of a metal-carbene- and Lewis-acid-bonded ylide intermediate in the assistance of a dual-tasking nickel(II) complex. An alternative chiral Lewis-acid-bonded ylide pathway
尽管使用经典的手性 Rh(II) 和 Cu(I) 催化剂证明锍叶立德的 [2,3]-σ 重排的高对映选择性(Doyle-Kirmse 反应)令人惊讶地难以捉摸,但原则上这是由于难以精细区分硫的异位孤对和锍叶立德硫的手性反转。在这里,我们展示了新的 α-重氮吡唑酰胺和手性 N, N'-二氧化镍 (II) 配合物催化剂的协同合并能够实现高度对映选择性的 Doyle-Kirmse 反应。吡唑酰胺取代基作为活化基团和导向基团,在双任务镍 (II) 配合物的帮助下,很容易形成金属-卡宾和路易斯酸键合的叶立德中间体。即使对于对称二烯丙基硫烷的反应,另一种手性路易斯酸键合的叶立德途径也大大提高了产物的对映纯度。在一系列芳基或乙烯基取代的 α-重氮吡唑胺和硫化物上进行的大多数转化都进行得很快(大多数情况下在 5-20 分钟内),结果非常好(收率高达 99%,ee 高达 96%),提供了一个突破在对映选择性