Ethanol is a considerable platform molecule in biomass conversion,which could be acquired in quantity through acetone-butanol-ethanol(ABE)fermentation.People have been working on the upgrading of ethanol to value adde...Ethanol is a considerable platform molecule in biomass conversion,which could be acquired in quantity through acetone-butanol-ethanol(ABE)fermentation.People have been working on the upgrading of ethanol to value added chemicals for decades.In the meantime,1-butanol and a series of value added products have been selectively generated through C–C bond coupling.In this mini-review,we focus on the recent advances in selective C–C bond formation over balanced Lewis acid-base catalysts such as modified metal oxide,mixed metal oxide,hydroxyapatite and zeolite confined transition metal oxide catalysts.Among them,Pd-MgAlO_x and Sr-based hydroxyapatite exhibit>70%1-butanol selectivity,while Zn——xZr_yO_z and Ta-Si BEA zeolite achieve>80%of isobutene and butadiene selectivity respectively.The mechanism and reaction pathway of C–C bond formation in each reaction system are described in detail.The correlation between C–C bond coupling and the acidity/basicity of the Lewis acid-base pairs from the surface of the catalysts are also discussed.展开更多
Aldehydes are perhaps the most versatile compounds that enable many C-C bond forming reactions,which are not amenable for other subclasses of carbonyl compounds.We report the first use of amides as surrogates of aldeh...Aldehydes are perhaps the most versatile compounds that enable many C-C bond forming reactions,which are not amenable for other subclasses of carbonyl compounds.We report the first use of amides as surrogates of aldehydes for C-C bond formation,namely,the direct Knoevenagel-type condensation based on amides.The one-pot method consists of controlled reduction of an amide with LDBIPA[LiAlH(iBu)2(OiPr)],Lewis acid-mediated release of a reactive iminium ion intermediate,nucleophilic addition,and in situ elimination of amine.The reaction shows good functional group tolerance.We also demonstrated that the Schwartz reagent could be used as an alternative of LDBIPA.The employment of nitromethane and a silyl enol ether as the nucleophiles opens an avenue for the unprecedented amide-based nitro-aldol condensation reaction and aldol condensation reaction,respectively.展开更多
基金supported by the National High Technology Research and Development Program of China (863 Program, 2012AA02A700)the National Natural Science Foundation of China (21221062)~~
基金supported by the “111 Project” of China (B18030) and Nankai University
文摘Ethanol is a considerable platform molecule in biomass conversion,which could be acquired in quantity through acetone-butanol-ethanol(ABE)fermentation.People have been working on the upgrading of ethanol to value added chemicals for decades.In the meantime,1-butanol and a series of value added products have been selectively generated through C–C bond coupling.In this mini-review,we focus on the recent advances in selective C–C bond formation over balanced Lewis acid-base catalysts such as modified metal oxide,mixed metal oxide,hydroxyapatite and zeolite confined transition metal oxide catalysts.Among them,Pd-MgAlO_x and Sr-based hydroxyapatite exhibit>70%1-butanol selectivity,while Zn——xZr_yO_z and Ta-Si BEA zeolite achieve>80%of isobutene and butadiene selectivity respectively.The mechanism and reaction pathway of C–C bond formation in each reaction system are described in detail.The correlation between C–C bond coupling and the acidity/basicity of the Lewis acid-base pairs from the surface of the catalysts are also discussed.
基金supported by the National Natural Science Foundation of China(21931010,21672176)the National Key Research and Development Program of China(2017YFA0207302)
文摘Aldehydes are perhaps the most versatile compounds that enable many C-C bond forming reactions,which are not amenable for other subclasses of carbonyl compounds.We report the first use of amides as surrogates of aldehydes for C-C bond formation,namely,the direct Knoevenagel-type condensation based on amides.The one-pot method consists of controlled reduction of an amide with LDBIPA[LiAlH(iBu)2(OiPr)],Lewis acid-mediated release of a reactive iminium ion intermediate,nucleophilic addition,and in situ elimination of amine.The reaction shows good functional group tolerance.We also demonstrated that the Schwartz reagent could be used as an alternative of LDBIPA.The employment of nitromethane and a silyl enol ether as the nucleophiles opens an avenue for the unprecedented amide-based nitro-aldol condensation reaction and aldol condensation reaction,respectively.
