Intramolecular alkene hydroamination and degradation of amidines: divergent behavior of rare earth metal amidinate intermediates
作者:Dexing Zhang、Ruiting Liu、Xigeng Zhou
DOI:10.1039/c8cy01481g
日期:——
and nitriles is also developed. Additionally, amidine reconstruction followed by an intramolecular alkene hydroamidination strategy for the synthesis of substituted imidazolines and tetrahydropyrimidines from secondary enamines and inactive amidines has also been established, which may circumvent the need for some unavailable starting materials. The mechanistic studies prove that these reactions proceed
A [3+3] cyclization strategy for asymmetric synthesis of alkyl substituted piperidine-2-ones using 1,2-cyclic sulfamidates: a formal synthesis of (S)-coniine from l-norvaline
作者:Abdullah Karanfil、Berrin Balta、Mustafa Eskici
DOI:10.1016/j.tet.2012.09.081
日期:2012.12
β-unsaturated esters after acidic hydrolysis. Hydrogenation of the unsaturated esters and subsequent thermal cyclization afforded the related alkyl substituted piperidine-2-ones. This approach represents a novel [3+3] cyclization strategy for the asymmetricsynthesis of alkyl substituted piperidin-2-ones. Efficiency of the cyclization process is illustrated by a formal asymmetricsynthesis of (S)-coniine from l-norvaline
A Proton-Responsive Annulated Mesoionic Carbene (MIC) Scaffold on Ir Complex for Proton/Hydride Shuttle: An Experimental and Computational Investigation on Reductive Amination of Aldehyde
作者:Pragati Pandey、Prosenjit Daw、Noor U Din Reshi、Kira R. Ehmann、Markus Hölscher、Walter Leitner、Jitendra K. Bera
DOI:10.1021/acs.organomet.0c00568
日期:2020.11.9
A Cp*Ir(III) complex (1) bearing a proton-responsive hydroxy unit on an annulated imidazo[1,2-a][1,8]naphthyridine based mesoionic carbene scaffold was synthesized by two different syntheticroutes. The molecular structure of 1 revealed an anionic lactam form of the ligand. The acid–base equilibrium between the lactam-lactim tautomers on the ligand scaffold was examined by 1H NMR and UV–vis spectra
通过两种不同的合成途径合成了在环状咪唑并[1,2- a ] [1,8]萘吡啶基介电卡宾骨架上带有质子响应性羟基单元的Cp * Ir(III)配合物(1)。的分子结构1揭示了配体的阴离子内酰胺形式。通过1 H NMR和UV-vis光谱检查了配体支架上内酰胺-内酯互变异构体之间的酸碱平衡。估算内酰胺形式为1的附件-OH基团的p K a,以评估催化剂的质子转移性能。1的催化功效通过使用三种不同的氢源(分子H 2,i PrOH / KO t Bu组合和HCOOH / Et 3 N(5:2)共沸混合物)评估醛的还原胺化反应。发现在三种不同的氢化方法中,HCOOH / Et 3 N(5:2)共沸混合物是最好的。在反应条件下,催化剂1在羰基上化学选择性地氢化亚胺。使用HCOOH / Et 3 N(5:2)共沸混合物将一系列醛还原为相应的仲胺。此外,催化剂1在还原多种N-杂环亚胺衍生物方面显示出高效率。提
A Simple, Broad-Scope Nickel(0) Precatalyst System for the Direct Amination of Allyl Alcohols
作者:Joseph B. Sweeney、Anthony K. Ball、Philippa A. Lawrence、Mackenzie C. Sinclair、Luke J. Smith
DOI:10.1002/anie.201805611
日期:2018.8.6
inexpensive NiII/Zn couple enables the allylation of primary, secondary, and electron‐deficient amines without the need for glove‐box techniques. Under mild conditions, primary and secondary aliphatic amines react smoothly with a range of allyl alcohols, giving secondary and tertiaryaminesefficiently. This “totally catalytic” method can also be applied to electron‐deficient nitrogen nucleophiles; the
Silylative Reductive Amination of α,β-Unsaturated Aldehydes: A Convenient Synthetic Route to β-Silylated Secondary Amines
作者:Eunae Kim、Sehoon Park、Sukbok Chang
DOI:10.1002/chem.201800958
日期:2018.4.17
Described here is a reductive amination/hydrosilylation cascade of α,β‐unsaturated aldehydes mediated by a Lewisacidic borane catalyst. The present reaction system provides an one‐pot synthetic route towards β‐silylated secondary amines that have not been accessible by other previous catalysis. Comparative 1H NMR studies on the silylative reduction of enimines revealed that steric bulkiness of primary
这里描述的是路易斯酸性硼烷催化剂介导的α,β-不饱和醛的还原胺化/氢化硅烷化级联。本反应系统提供了一种单罐合成路线,可通往其他先前催化无法达到的β-甲硅烷基化仲胺。对亚胺的甲硅烷基化还原进行的比较1 H NMR研究表明,伯胺反应物的空间体积极大地影响了催化效率和区域选择性。该策略适用于广泛的底物,并适用于一锅克级合成。此外,还发现非对映选择性地引入β-甲硅烷基是可行的(dr高达71:29)。