通过一锅S N 2'烯丙基化-Wittig策略从磷鎓叶立德,烯丙基碳酸酯和醛中无催化剂地合成烷基二烯
摘要:
提出了通过区域选择性的S N 2'方法将稳定的磷化磷与烯丙基碳酸酯进行无催化剂的烯丙基烷基化反应。随后的与脂肪族和芳香族醛以及乙烯酮的一锅Wittig反应可提供结构多样的跳跃式二烯(1,4-二烯),且产率高,并且具有灵活的取代基图案,具有中等至出色的立体选择性。这种单锅S N 2'烯丙基化-维蒂希(Wittig)策略构成了一种方便有效的合成方法,用于从容易获得的起始原料中高度官能化的二烯。
Direct Synthesis of Dihydropyrrolo[2,1‐
<i>a</i>
]Isoquinolines through FeCl
<sub>3</sub>
Promoted Oxidative Aromatization
作者:Hai‐Lei Cui、Lu Jiang、Hao Tan、Si Liu
DOI:10.1002/adsc.201900756
日期:2019.10.22
We have developed a straightforward FeCl3 promoted synthesis of dihydropyrrolo[2,1‐a]isoquinolinesthrough formal (3+2) cycloaddition/oxidative aromatization cascade of dihydroisoquinoline with Morita‐Baylis‐Hillman carbonates (up to 96% yield). Further modifications of the obtained products were successful through simple chemical transformations providing a diverse range of natural product‐like molecules
我们已经开发出一种简单的FeCl 3促进的二氢吡咯并[2,1- a ]异喹啉的合成,方法是通过二氢异喹啉与Morita-Baylis-Hillman碳酸盐的正式(3 + 2)环加成/氧化芳构化级联(产率高达96%)。通过简单的化学转化成功获得了进一步的修饰产物,提供了多种天然产物样分子(12个例子)。
Enantioselective synthesis of spirocyclic cyclopentenes: asymmetric [3+2] annulation of 2-arylideneindane-1,3-diones with MBH carbonates derivatives catalyzed by multifunctional thiourea–phosphines
作者:Fangle Hu、Yin Wei、Min Shi
DOI:10.1016/j.tet.2012.07.013
日期:2012.9
The [3+2] annulation reactions of 2-arylideneindane-1,3-diones with Morita–Baylis–Hillman (MBH) carbonates proceeded smoothly in the presence of multifunctional thiourea–phosphines to produce the corresponding quaternary carbon centered spirocyclic cyclopentenes in moderate yields, with high diastereoselectivities and enantioselectivities under mild conditions. The plausible reaction has been also
Cooperative Rh(II)/Pd(0) Dual Catalysis: Synthesis of Highly Substituted 3(2<i>H</i>)-Furanones with a C2-Quaternary Center via a Cyclization/Allylic Alkylation Cascade of α-Diazo-δ-keto-esters
cyclization/allylic alkylation cascade of stable α-diazo-δ-keto-esters has been developed. Highly substituted 3(2H)-furanones with a C2-quaternary center can be obtained efficiently under mild conditions via one-pot synthesis. Remarkably, this binary catalytic system shows high chemo-, regio-, and stereoselectivity and excellent tolerance to various functionalities.
Catalytic Enantioselective Vinylogous Allylic Alkylation of Coumarins
作者:Satavisha Kayal、Santanu Mukherjee
DOI:10.1021/acs.orglett.7b02421
日期:2017.9.15
An unprecedented, organocatalytic enantioselective vinylogous γ-allylic alkylation of 4-methylcoumarins has been developed. Using allylic carbonates as the allyl source, this reaction is catalyzed by Lewis basic dimeric Cinchona alkaloid (QD)2PHAL and proceeds exclusively in a γ- and branched-selective manner to produce densely functionalized coumarin derivatives generally in good yields with good
Asymmetric [3+2] Cycloaddition of Olefins with Morita–Baylis–Hillman Carbonates Catalyzed by BINOL-Based Bifunctional Phosphine
作者:Hai-Lei Cui、Xue Tang、Meng-Fan Li、Xing-Jie Xu、Yin Shi
DOI:10.1055/s-0037-1611752
日期:2019.4
series of novel BINOL-based phosphines. These bifunctional organocatalysts can be used in the [3+2] cycloaddition of electron-deficient olefins and Morita–Baylis–Hillman (MBH) carbonates. Moderate to excellent yields (up to >99%) and good to excellent enantioselectivities (up to 95% ee) can be obtained in the cycloaddition reaction of maleimides and MBH carbonates. The application of these novel phosphines