| Hydroformylation refers to the process in which olefins react with syngas（CO/H2）to produce aldehydes with one more carbon atom,which is widely used in industry.Aldehydes,the products of hydroformylation,have relatively active properties and can be further reacted to produce acetals.The construction of the“hydroformylation-acetalization”has been widely concerned.This work focuses on the hydroformylation and the tandem“hydroformylation-acetalization”ofα-olefins,the related works were carried out from the following aspects:Hydroformylation of aliphaticα-olefins:The regioselectivity of aliphaticα-olefins in the hydroformylation reaction was the difficulty and research hotspot of the reaction,it lies in the selection of the catalytic system and the adjustment of the process conditions.By using Dicarbonylacetylacetonato rhodium Rh（acac）（CO）2 and the bidentate phosphine ligand 9,9-Dimethyl-4,5-bis（diphenylphosphino）xanthene（Xantphos）for the reaction of 1-octene,the conversion of 1-octene could reach 99%,the yields of linear aldehydes were 93%,and the L/B was 31.0.Substrate universal research shows that highe conversion and regional selectivity could be obtained when different aliphaticα-olefins were involved in the reaction,L/B was between 30-32.“Tertiary phosphine-SO3H”bifunctional ligand modified Rh catalyzes the tandem“hydroformylation-acetalization”ofα-olefins:The Br?nsted organic acid groups（-SO3H）was introduced into the tertiary phosphine ligand to construct a bifunctional ligand for Rh-catalyzed“hydroformylation-acetalization”ofα-olefins.It was found that when 1-hexene and Me OH reacted at 100°C in the presence of sulfonated 9,9-Dimethyl-4,5-bis（diphenylphosphino）xanthene（Xantphos-SO3H）,the conversion of 1-hexene could reach99%,the yield of acetals were 92%,only 5%of aldehydes were not converted.Substrate universal research shows that this system could achieve ideal catalytic effects when applied to different aliphatic and aromaticα-olefins.When ethylene glycol was involved in the acetalization,the conversion of olefins was as high as 100%,and the selectivity of acetals was98%,the presence of intermediate aldehydes was almost impossible to detect.Further research showed that ionic ligand Xantphos-SO3H could be fixed in the ionic liquids together with the catalyst to realize the recovery and recycling of the catalytic system.Good catalytic effects could be found after 6 cycles of the reaction by adding the ionic liquid1-Butyl-3-methylimidazolium tetrafluoroborate（[Bmim]BF4）to the reaction system.The tandem“hydroformylation-acetalization”ofα-olefins catalyzed by Ir with H2O as hydrogen source:The“hydroformylation-acetalization”ofα-olefins could be reslized by using the physical addition system Chloro（1,5-cyclooctadiene）iridium（I）dimer（[Ir（COD）Cl]2）and Lewis acid（Al Cl3）.By means of segmented heating,when 1-hexene and Me OH was used to the“hydroformylation-acetalization”,the conversion was 99%,and the oxidation product yields were 87%,of which acetals accounted for 88%.Hydrogen generated in-situ through the water-gas shift process could reduce the yields of hydrogenation by-products to 3%.Substrate universal research shows that different aliphatic and aromaticα-olefins could achieve good results in“hydroformylation-acetalization”.The formation of Ir-H active species was observed by 1H NMR,according to the isotopic tracer method,H2O was proved to be the hydrogen source of the reaction by comparing the reaction of H2O and D2O. |
