Synthesis of 1,3‐Dioxan‐2‐ones by Photo‐Aerobic Selenium‐π‐Acid Multicatalysis
摘要:
AbstractAn expedient method for the synthesis of cyclic carbonates from homoallylic carbonic acid esters by means of photo‐aerobic selenium‐π‐acid multicatalysis is reported. Until now, conceptually related methods commonly relied either on the stoichiometric addition of electrophiles onto the substrate's alkene moiety or the presence of pre‐installed leaving groups in allylic position of said alkene to – in part, catalytically – initiate an intramolecular attack by an adjacent carbonic acid ester group. In sharp contrast, the current study shows that the C−C double bond of homoallylic carbonic acid esters can be directly activated by the catalytic interplay of a pyrylium dye and a diselane using ambient air as the sole oxidant and visible light as an energy source.
Synthesis of 1,3‐Dioxan‐2‐ones by Photo‐Aerobic Selenium‐π‐Acid Multicatalysis
摘要:
AbstractAn expedient method for the synthesis of cyclic carbonates from homoallylic carbonic acid esters by means of photo‐aerobic selenium‐π‐acid multicatalysis is reported. Until now, conceptually related methods commonly relied either on the stoichiometric addition of electrophiles onto the substrate's alkene moiety or the presence of pre‐installed leaving groups in allylic position of said alkene to – in part, catalytically – initiate an intramolecular attack by an adjacent carbonic acid ester group. In sharp contrast, the current study shows that the C−C double bond of homoallylic carbonic acid esters can be directly activated by the catalytic interplay of a pyrylium dye and a diselane using ambient air as the sole oxidant and visible light as an energy source.
Regio- and <i>Trans</i>-Selective Ni-Catalyzed Coupling of Butadiene, Carbonyls, and Arylboronic Acids to Homoallylic Alcohols under Base-Free Conditions
作者:Yu-Qing Li、Guang Chen、Shi-Liang Shi
DOI:10.1021/acs.orglett.1c00488
日期:2021.4.2
We herein report a Ni-catalyzed three-component coupling of 1,3-butadiene, carbonylcompounds, and arylboronic acids as a general synthetic approach to 1,4-disubstituted homoallylic alcohols, an important class of compounds, which have previously not been straightforward to access. The reaction occurs efficiently using a Ni(cod)2 catalyst without any external base and ligand at ambient temperature
A mild and practical oxyarylation of alkenes by oxidative radical addition has been developed by using aerobic oxidation of hydrazine compounds. The use of a catalytic amount of potassiumferrocyanidetrihydrate (K4[Fe(CN)6]⋅3 H2O) and water accelerated this radical reaction to give peroxides or alcohols from simple alkenes in good yields. The environmentally friendly and economical radical reactions
Nickel-catalysed three-component connection reaction of a phenyl group, conjugated dienes, and aldehydes: stereoselective synthesis of (E)-5-phenyl-3-penten-1-ols and (E)-3-methyl-5-phenyl-3-penten-1-ols
presence of 10 mol% of Ni(acac)2, Ph2Zn reacts with 1,3-butadiene and aldehydes at room temperature to give 1-alkyl and 1-aryl substituted (E)-5-phenyl-3-penten-1-ols (3) in good yields. Under similar conditions, the three components of Ph3BZnEt2, isoprene, and aldehydes combine with each other to furnish 1-alkyl and 1-aryl substituted (E)-3-methyl-5-phenyl-3-penten-1-ols (5) in good yields.
Linear 1:1:1 coupling of dimethylzinc, 1,3-dienes, and carbonyl compounds in this order is facilitated by catalytic amounts of [Ni(acac)(2)] to give (E)-3-hexen-1-ols in good yields under mild conditions [Eq. (a)]. Increasing steric hindrance at the carbonyl group favors formation of the 1:2:1 adduct, and this is the sole product when the carbonyl compound is acetone. acac=acetylacetonate.
We herein report a Ni-catalyzed three-component cross-electrophile coupling of 1,3-dienes with aldehydes and arylbromides using manganese metal as the reducing agent. This efficient protocol accomplishes dicarbofunctionalization of 1,3-dienes to synthesize diverse structural 1,4-disubstituted homoallylic alcohols by forming two new C–C bonds in one time. Mechanistic study suggests that an allyl-nickel(I)
我们在此报道了使用锰金属作为还原剂的 1,3-二烯与醛和芳基溴化物的 Ni 催化的三组分交叉亲电偶联。这种有效的方案通过一次形成两个新的 C-C 键来完成 1,3-二烯的二碳官能化,从而合成不同结构的 1,4-二取代高烯丙醇。机理研究表明,烯丙基镍 (I) 物种参与了催化循环。