Probing the Mechanism of Allylic Substitution of Morita–Baylis–Hillman Acetates (MBHAs) by using the Silyl Phosphonite Paradigm: Scope and Applications of a Versatile Transformation
作者:Maria Kalyva、Alexandros L. Zografos、Era Kapourani、Evaggelos Giambazolias、Laurent Devel、Athanasios Papakyriakou、Vincent Dive、Yannis G. Lazarou、Dimitris Georgiadis
DOI:10.1002/chem.201405626
日期:2015.2.16
using 31P NMR spectroscopy revealedunexpected reactivity differences between ester and nitrile derivatives. These kinetic profiles and DFT calculations support a mechanistic scenario in which observed differences can be explained from the “lateness” of transition states. In addition, we provide experimental evidence suggesting that enolates due to initial P‐Michaeladdition are not formed. Based on
AP 甲硅烷基膦酸酯和森田-的Baylis-希尔曼乙酸盐(MBHAs)之间C键形成反应探索作为向医药相关β-carboxyphosphinic结构基序的通用的替代方案。使用31记录的不同取代的MBHA转化为次膦酸9或14的转化率P NMR光谱显示酯和腈衍生物之间的反应性差异出乎意料。这些动力学曲线和DFT计算支持了一种机械方案,其中可以从过渡态的“迟缓”解释观察到的差异。此外,我们提供的实验证据表明,由于最初的P-Michael加成而形成的烯醇不形成。基于拟议的机械情景结合DFT计算,对E / Z的解释提出了酯和腈之间的立体选择性差异。提出了由这种转变产生的合成机会,该机会涉及几种合成的反复变化的膦基结构单元的制备,而这些结构单元通过经典的P-Michael合成路线的访问并不简单。
The Enantioselective Synthesis of Chiral Carbocyclic Nucleosides via Palladium‐Catalyzed Asymmetric Allylic Amination of Alicyclic MBH Adducts with Purines
作者:Bo Kang、Qi‐Ying Zhang、Gui‐Rong Qu、Hai‐Ming Guo
DOI:10.1002/adsc.202000088
日期:2020.5.12
The enantioselective synthesis of carbocyclic nucleosides through the palladium‐catalyzed asymmetric allylic amination of alicyclic Morita‐Baylis‐Hillman (MBH) adducts with purines was successfully developed. With a combination of Pd2(dba)3/L7 as catalyst, various optically active carbocyclic nucleosides featuring a C=C double bond in the carbocycle moiety were obtained in high yields (up to 97%) with
Concise formal synthesis of (−)-7-deoxyloganin via N-heterocyclic carbene catalysed rearrangement of α,β-unsaturated enol esters
作者:Lisa Candish、David W. Lupton
DOI:10.1039/c1ob05953j
日期:——
NHC catalysedrearrangement of α,β-unsaturated enol esters derived from formyl acetates and cyclopentyl annulated α,β-unsaturated acids provides the cyclopentapyranone core of (−)-7-deoxyloganin (1) with diastereo- and chemoselectivity in 6 steps starting from (−)-citronellal. The elaboration to the natural product has been investigated using two new approaches. The most successful intercepts our previous
Substitution nucleophile d'acetates de cyclenols allyliques fonctionnels par des organometalliques en presence de sels cuivreux. Application a une synthese rapide de la (±)mitsugashiw alactone
作者:Hassen Amri、Monique Rambaud、Jean Villieras
DOI:10.1016/s0040-4020(01)81522-2
日期:1990.1
Substitution of functional allylic cycloalkenol acetates by Grignardreagents (primary , secondary, tertiary-alkyl, vinyl, aryl) in the presence of a catalytic amount (2.5% equivalent) of cuprous iodide at low temperature, gives high yields of various functional α-substituted cycloalkenes . The reaction can be applied to lithium enolates of esters and need no catalyst, but may be performed with HMPA
Phosphinic pseudo-peptide derivatives for the selective inhibition of the active c-terminal site of angiotensin converting enzyme (I) (ace)
申请人:Cotton Joel
公开号:US20050070505A1
公开(公告)日:2005-03-31
The invention relates to the use of phosphinic pseudopeptide derivatives for production of a medicament for selectively inhibiting the active C-terminal site of angiotensin I converting enzyme. These derivatives are of formula (II):
where, R
1
may be a protecting group for amino functions usually used in peptide chemistry or an amino acid or a peptide protected by the above type of protecting groups, R
2
and R
3
correspond to a natural or unnatural amino acid side chain and R
4
and R
5
represent a hydrogen atom or a counterion.
Applications: prevention and treatment of cardiovascular diseases in humans.