当在等价的TsOH存在下用1,2-二醇处理时,酰基呋喃3提供了甲苯磺酸化的二醇单酯5。此过程可能通过中间呋喃基缩酮的Protoodefuranation形成1,3-dioxolan-2-ylium阳离子8发生。随后通过对甲苯磺酸的S N 2亲核取代而开环,然后提供酯5。当使用1,3-二醇时,通过表观的醇醛二聚/片段化途径形成了含呋喃的酯9而不是标准产物。
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。
Lithium tert-butoxide mediated α-alkylation of ketones with primary alcohols under transition-metal-free conditions
LiOtBu was found to efficiently promote the α-alkylation reaction of ketones with primary alcohols, without the addition of any transition metal catalyst.
Direct conversion of secondary propargyl alcohols into 1,3-di-arylpropanone <i>via</i> DBU promoted redox isomerization and palladium assisted chemoselective hydrogenation in a single pot operation
作者:Rimpa De、S. Antony Savarimuthu、Shubhadeep Chandra、Mrinal K. Bera
DOI:10.1039/d1nj02972j
日期:——
Palladium(II)acetate is found to be an efficient catalyst for the single-step conversion of secondary propargyl alcohols to 1,3-diarylpropanone derivatives under mild basic conditions. The reaction is believed to proceed via redox isomerisation of secondary propargyl alcohols followed by chemoselective reduction of an enone double bond with formic acid as an adequate hydrogen donor. A large number
发现乙酸钯 ( II ) 是一种有效的催化剂,可在温和的碱性条件下将仲炔醇一步转化为 1,3-二芳基丙酮衍生物。据信,该反应通过仲炔丙醇的氧化还原异构化,然后用甲酸作为适当的氢供体对烯酮双键进行化学选择性还原而进行。大量的 1,3-二芳基丙酮衍生物可以很容易地从毫克级到几克级制备。