N芳基丙烯酰胺在Pd催化下的分子内不对称碳环合钯,然后使用乙硼酸水作为氢化物源还原C(sp 3)-Pd中间体,从而以高收率和对映选择性提供了对映体富集的3,3-二取代的吲哚。当重水与双(邻苯二酚)二硼(Cat 2 B 2)一起用作氘供体时,氘以高合成效率掺入产品中。配体决定了反应的对映选择性和反应路径,从而提供了氢芳基化(还原性Heck)或碳硼化产物。
Pd-Catalyzed Heck-Type Cascade Reactions with <i>N</i>-Tosyl Hydrazones: An Efficient Way to Alkenes via in Situ Generated Alkylpalladium
作者:Xianglei Liu、Xinna Ma、Yunze Huang、Zhenhua Gu
DOI:10.1021/ol402210a
日期:2013.9.20
A palladium-catalyzedHeck-type cascade reaction of aryl halides and N-tosyl hydrazones is reported. The neopentylpalladium species, generated from an intramolecular Heck-type insertion reaction of aryl halides, could efficiently react with carbenes to form highly functionalized alkenes. The synthesis of spiro compounds was also explored via a multiple Heck-type insertion reaction with N-tosyl hydrazone
A decarboxylation reaction of a (3-methyl-3-butenyl)malonic acid dialkyl ester, carried out by heating in the presence of water and a base, produces an alkyl 5-methyl-5-hexenoate. The decarboxylation reaction produces the alkyl 5-methyl-5-hexenoate inexpensively and effectively. The base can optionally be a tertiary amine compound or a heterocyclic amine compound. Producing the alkyl 5-methyl-5-hexenoate can optionally further include removing an alcohol.
Cu(II)-Catalyzed Olefin Migration and Prins Cyclization: Highly Diastereoselective Synthesis of Substituted Tetrahydropyrans
作者:Arun K. Ghosh、Daniel R. Nicponski
DOI:10.1021/ol2016675
日期:2011.8.19
an appropriate bisphosphine ligand have been shown to effectively catalyze the formation of substituted tetrahydropyrans via a sequential olefin migration and Prins-type cyclization. This methodology provides convenient access to a variety of functionalized tetrahydropyrans in excellent diastereoselectivities and good to excellent yields.
Various halogenated α‐exo‐methylene‐γ‐butyrolactones and α‐exo‐methylene‐δ‐valerolactones were obtained in high yields and enantioselectivities. The resulting enantioenriched halogenated α‐exo‐methylene‐lactones were found to exhibit significant tumor‐inhibiting activities.