[IrCp*(NCMe)
<sub>2</sub>
(PPh
<sub>2</sub>
Me)][PF
<sub>6</sub>
]
<sub>2</sub>
as Catalyst for the Meyer–Schuster Rearrangement of Arylpropargylic Alcohols under Mild Conditions
The novel iridium complex [IrCp*(NCMe)2(PPh2Me)][PF6]2 (I) efficiently catalyzed the Meyer–Schusterrearrangement of selected arylpropargylic alcohols into α,β-unsaturated aldehydes under mild conditions and without the need of a co-catalyst. A mechanism involving a (hydroxy)alkenylcarbene intermediate is proposed.
Mizoroki–Heck reaction of 1,2-disubstituted aryl alkenes: Variables of synthesis, solvent and ligand modulation of reactivity
作者:Pronnoy G. Bangar、Priyanka R. Jawalkar、Swapnil R. Dumbre、Pallavi K. Raut、Dharmaraj J. Patil、Neethu Tv、Shana Sudhakaran、Suresh Iyer
DOI:10.1080/00397911.2020.1811986
日期:2020.12.16
Abstract Reaction of aryl iodides with 1,2-disubstituted aryl alkenes in the presence of TBABr/TBACl gave high yields of the Mizoroki–Heck product. Phosphine ligands were used for the modulation of reactivity and stereoselectivity, for the reaction of 4-iodoanisole with cinnamaldehyde. tert-Bu3P.HBF4 gave the highest E:Z ratio of 1:0.08. The use of PEG-200 and PEG-400 as solvent could activate the
The Heck arylation of mono- and disubstituted olefins catalyzed by palladium supported on alumina-based oxides
作者:Ewa Mieczyńska、Andrzej Gniewek、Iweta Pryjomska-Ray、Anna M. Trzeciak、Hanna Grabowska、Mirosław Zawadzki
DOI:10.1016/j.apcata.2010.11.041
日期:2011.2
With the same catalysts, good results, up to 97% yield of ethyl β-phenylcinnamate (3), were also obtained in the coupling of bromobenzene with ethyl cinnamate. The three most active catalysts, Pd(0)/Al2O3, Pd(II)/Al2O3, and Pd(II)/Al2O3–Fe2O3, were applied in the Heck cross-coupling of cinnamates with different bromobenzene and iodobenzene derivatives, leading to β-arylcinnamate products. The highest
通过醇盐溶胶-凝胶法(Al 2 O 3,Al 2 O 3 -ZrO 2,Al 2 O 3 -ZrO 2 -Eu 2制备)负载在氧化铝基混合氧化物上的含Pd(0)或Pd(II)的钯催化剂O 3,Al 2 O 3 –MgO,Al 2 O 3 –CeO 2,Al 2 O 3 –Fe 2 O 3)在DMF溶剂中对溴苯与丙烯酸丁酯的Heck偶联非常有效。在过量的溴苯存在下,4小时后形成肉桂酸丁酯(1)作为主要产物。使用相同的催化剂,在溴苯与肉桂酸乙酯的偶联中也获得了良好的结果,β-苯基肉桂酸乙酯(3)的产率高达97%。三种活性最高的催化剂Pd(0)/ Al 2 O 3,Pd(II)/ Al 2 O 3和Pd(II)/ Al 2 O 3 –Fe 2 O 3分别用于肉桂酸与不同的溴苯和碘苯衍生物的Heck交叉偶联,生成β-芳基肉桂酸酯产品。当碘代茴香醚和肉桂醛用作底物时,观察到最高产率。通过TEM测量证
Chiral dihydrobenzo[1,4]oxazines as catalysts for the asymmetric transfer-hydrogenation of α,β-unsaturated aldehydes
作者:Christian Ebner、Andreas Pfaltz
DOI:10.1016/j.tet.2011.10.051
日期:2011.12
A new class of organocatalysts based on the structure of 2,3-dihydrobenzo[1,4]oxazine was prepared and applied in the enantioselective transfer-hydrogenation of α,β-unsaturatedaldehydes with Hantzsch ester as hydride donor. These catalysts proved to be particularly effective for the conjugate reduction of β,β-diaryl-substituted acrylaldehydes leading to saturated aldehydes bearing a stereogenic center
Palladium-Catalyzed Cascade Saegusa-Heck Reaction: Synthesis of β,β-Diarylacroleins from Arylpropanals and Aryl Iodides
作者:Li Xiao、Yilin Zheng、Qiong Xie、Liming Shao
DOI:10.1002/ejoc.201701025
日期:2017.10.25
An efficient Pd-catalyzed Saegusa–Heck cascade protocol for the preparation of synthetically useful β,β-diarylacroleins in moderate to high yields (30–83 %) from arylpropanals and aryl iodides is developed.