Syntheses of (1R,2S,3R,4S)-1,7,7-trimethyl-2-pyridin-2-ylmethylbicyclo[2.2.1]-heptane-2,3-diol (7), (1R,2S,3R,4S)-1,7,7-trimethyl-2-[(6-methyl)-pyridin-2-ylmethyl-bicyclo-[2.2.1]heptane-2,3-diol (13), and (1R,2S,2’R,...Syntheses of (1R,2S,3R,4S)-1,7,7-trimethyl-2-pyridin-2-ylmethylbicyclo[2.2.1]-heptane-2,3-diol (7), (1R,2S,3R,4S)-1,7,7-trimethyl-2-[(6-methyl)-pyridin-2-ylmethyl-bicyclo-[2.2.1]heptane-2,3-diol (13), and (1R,2S,2’R,4R)-1,7,7-trimethyl-2-piperidin-2-ylmethyl-bicyclo[2.2.1]heptan-2-ol (19b) from commercially available (d)-camphor (1) are described. Key steps of the syntheses involved substrate-controlled diastereoselective alkylation and platinum oxide-catalyzed hydrogenation reactions. These compounds, and other intermediate amino alcohols in their syntheses, were successfully utilized as ligands in enantioselective diethyl zinc (Et2Zn) addition to benzaldehyde with moderate enantioselectivity.展开更多
A complete study of the asymmetric addition of phenylacetylene to ketones catalyzed by Schiff-base amino alcohol-Zn complex is reported in this article. The Schiff-base amino alcohols were easily prepared from amino a...A complete study of the asymmetric addition of phenylacetylene to ketones catalyzed by Schiff-base amino alcohol-Zn complex is reported in this article. The Schiff-base amino alcohols were easily prepared from amino acids in three steps. When the amount of ligand was 1%（molar fraction）, an e.e. value up to 94% was obtained. A series of practical chiral ligands were applied in the enantioselective addition of phenylacetylene to ketones without adding another stronger Lewis acid except zinc.展开更多
Electrochemical alcohol oxidation,the alternate of oxygen evolution reaction,has been recognized as an effective way to produce value-added chemicals coupled with H2 production.However,the current researches still suf...Electrochemical alcohol oxidation,the alternate of oxygen evolution reaction,has been recognized as an effective way to produce value-added chemicals coupled with H2 production.However,the current researches still suffer from the low reaction rate and Faradaic efficiency(FE)that limits the overall efficiency.Herein,we report a ligand intercalation strategy to enhance the current density of alcohol electrooxidation by intercalating sodium dodecyl sulfonate(SDS)in the interlayer of Co(OH)_(2)catalyst(Co(OH)_(2)-SDS).For instance,the Co(OH)_(2)-SDS shows obviously enhanced current density for glycerol electrooxidation than that of pure Co(OH)_(2).The corresponding glycerol conversion rate and H2 production rate reach 0.35 mmol·cm^(−2)·h^(−1)and 9.1 mL·cm^(−2)·h^(−1)at 1.42 V vs.reversible hydrogen electrode,which are 2.2-and 1.9-fold higher than that of Co(OH)_(2).The yield of formate reaches 86.6%with selectivity of 95.3%at high glycerol conversion of 95.1%(with FE of 83.3%for glycerol oxidation).The Co(OH)_(2)-SDS is demonstrated efficient for different alcohols with enhanced performance.We confirmed that the intercalation of SDS in Co(OH)_(2)can promote the generation and exposure of CoOOH reactive sites,and also facilitate the adsorption of alcohol,thus enabling high reaction rate.展开更多
文摘Syntheses of (1R,2S,3R,4S)-1,7,7-trimethyl-2-pyridin-2-ylmethylbicyclo[2.2.1]-heptane-2,3-diol (7), (1R,2S,3R,4S)-1,7,7-trimethyl-2-[(6-methyl)-pyridin-2-ylmethyl-bicyclo-[2.2.1]heptane-2,3-diol (13), and (1R,2S,2’R,4R)-1,7,7-trimethyl-2-piperidin-2-ylmethyl-bicyclo[2.2.1]heptan-2-ol (19b) from commercially available (d)-camphor (1) are described. Key steps of the syntheses involved substrate-controlled diastereoselective alkylation and platinum oxide-catalyzed hydrogenation reactions. These compounds, and other intermediate amino alcohols in their syntheses, were successfully utilized as ligands in enantioselective diethyl zinc (Et2Zn) addition to benzaldehyde with moderate enantioselectivity.
基金the National Natural Science Foundation of China(Nos.20472026 and 20525206)Chang Jiang Scholar Program of the Ministry of Education, China.
文摘A complete study of the asymmetric addition of phenylacetylene to ketones catalyzed by Schiff-base amino alcohol-Zn complex is reported in this article. The Schiff-base amino alcohols were easily prepared from amino acids in three steps. When the amount of ligand was 1%（molar fraction）, an e.e. value up to 94% was obtained. A series of practical chiral ligands were applied in the enantioselective addition of phenylacetylene to ketones without adding another stronger Lewis acid except zinc.
基金supported by the National Natural Science Foundation of China(No.22105026)the Science and Technology Project of Beijing Education Commission(No.KM202110017004),the Natural Science Foundation of Beijing Municipality(No.2184102)+1 种基金the Beijing Talent Training Foundation(No.2017000020124G082)the URT Program of Beijing Institute of Petrochemical Technology(Nos.2022J00053 and 2021J00106).
文摘Electrochemical alcohol oxidation,the alternate of oxygen evolution reaction,has been recognized as an effective way to produce value-added chemicals coupled with H2 production.However,the current researches still suffer from the low reaction rate and Faradaic efficiency(FE)that limits the overall efficiency.Herein,we report a ligand intercalation strategy to enhance the current density of alcohol electrooxidation by intercalating sodium dodecyl sulfonate(SDS)in the interlayer of Co(OH)_(2)catalyst(Co(OH)_(2)-SDS).For instance,the Co(OH)_(2)-SDS shows obviously enhanced current density for glycerol electrooxidation than that of pure Co(OH)_(2).The corresponding glycerol conversion rate and H2 production rate reach 0.35 mmol·cm^(−2)·h^(−1)and 9.1 mL·cm^(−2)·h^(−1)at 1.42 V vs.reversible hydrogen electrode,which are 2.2-and 1.9-fold higher than that of Co(OH)_(2).The yield of formate reaches 86.6%with selectivity of 95.3%at high glycerol conversion of 95.1%(with FE of 83.3%for glycerol oxidation).The Co(OH)_(2)-SDS is demonstrated efficient for different alcohols with enhanced performance.We confirmed that the intercalation of SDS in Co(OH)_(2)can promote the generation and exposure of CoOOH reactive sites,and also facilitate the adsorption of alcohol,thus enabling high reaction rate.
