Electrochemical 1,4-reduction of α,β-unsaturated ketones with methanol and ammonium chloride as hydrogen sources
作者:Binbin Huang、Yanan Li、Chao Yang、Wujiong Xia
DOI:10.1039/c9cc02368b
日期:——
sustainable, chemoselective 1,4-reduction of α,β-unsaturatedketones by means of an electrochemical method is presented, wherein the extremely inexpensive ammonium chloride (NH4Cl) is applied as the only additive. The reaction proceeds smoothly in the air at ambient temperature. Mechanistic studies reveal that both NH4Cl and solvent methanol work as hydrogen donors.
Chemoselective Hydrosilylation of the α,β-Site Double Bond in α,β- and α,β,γ,δ-Unsaturated Ketones Catalyzed by Macrosteric Borane Promoted by Hexafluoro-2-propanol
作者:Xiao-Yu Zhan、Hua Zhang、Yu Dong、Jian Yang、Shuai He、Zhi-Chuan Shi、Lei Tang、Ji-Yu Wang
DOI:10.1021/acs.joc.0c00568
日期:2020.5.15
The B(C6F5)3-catalyzed chemoselective hydrosilylation of α,β- and α,β,γ,δ-unsaturated ketones into the corresponding non-symmetric ketones in mild reaction conditions is developed. Nearly 55 substrates including those bearing reducible functional groups such as alkynyl, alkenyl, cyano, and aromatic heterocycles are chemoselectively hydrosilylated in good to excellent yields. Isotope-labeling studies
An effective strategy for synthesis of Cu nanoparticles is designed, these nanoparticles have high catalytic activity in conjugate addition of B2(pin)2 and α,β-unsaturatedketones. The reaction of protodeboration can proceed with adding NaOtBu. In this way, a new method to reduce the conjugated alkenes of α,β-unsaturatedketones is developed with organoboranes as intermediates. Cu nanocrystals also
设计了一种有效的合成铜纳米颗粒的策略,这些纳米颗粒在B 2(pin)2和α,β-不饱和酮的共轭添加中具有高催化活性。原脱硼的反应可以通过添加NaO t Bu来进行。以这种方式,开发了一种以有机硼烷为中间体,还原α,β-不饱和酮的共轭烯烃的新方法。Cu纳米晶体在克级反应和循环利用实验中也具有优异的性能。提出了一种可能的机制。
Preparation of tetrahydroindolizines from pyridinium and isoquinolinium ylides
作者:Alan R. Katritzky、Nicholas E. Grzeskowiak、Julio Alvarez-Builla
DOI:10.1039/p19810001180
日期:——
Carbonyl- and nitrile-stabilised pyridinium and cyclic azonium methylides condense with chalcones to form tetrahydroindolizines and analogous fused pyrrolidines. The stereochemistry is illuminated by 13C and 1H n.m.r. spectroscopy. Several incorrect literature structures are rectified.
羰基和腈稳定的吡啶鎓和环状的偶氮鎓甲基化物与查耳酮缩合,形成四氢吲哚并二苯并类似的稠合吡咯烷。立体化学由13 C和1 H nmr光谱照亮。纠正了一些错误的文献结构。
Chiral Sc<sup>III</sup>–<i>N</i>,<i>N</i>′-Dioxide-Catalyzed 1,3-Dipolar Cycloaddition of Diaziridines with Chalcones
enantioselective 1,3-dipolarcycloaddition of meso-diaziridines with chalcones was realized by utilizing the ScIII-N,N'-dioxide complex as the catalyst. In this transformation, the 1,3-dipole intermediates generated from the C-N bond cleavage of diaziridine were trapped by chiral N,N'-dioxide/scandium(III) complex activated chalcones to undergo enantioselective 1,3-dipolarcycloaddition. A range of chiral