{"id":51129,"date":"2024-10-14T17:06:05","date_gmt":"2024-10-14T09:06:05","guid":{"rendered":"http:\/\/www.newtopchem.com\/archives\/51129"},"modified":"2024-10-14T17:06:05","modified_gmt":"2024-10-14T09:06:05","slug":"study-on-the-catalytic-effect-and-selectivity-of-cyclohexylamine-in-organic-synthesis-reactions","status":"publish","type":"post","link":"http:\/\/www.newtopchem.com\/archives\/51129","title":{"rendered":"Study on the catalytic effect and selectivity of cyclohexylamine in organic synthesis reactions","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"
Cyclohexylamine (CHA), as a common organic compound, has important application value in the field of organic synthesis. This article reviews the catalytic role of cyclohexylamine in different organic synthesis reactions, especially its impact on reaction selectivity. Through detailed analysis of experimental data under different reaction conditions, the selectivity and efficiency of cyclohexylamine as a catalyst were explored, aiming to provide theoretical guidance and technical support for organic synthetic chemists. <\/p>\n
Cyclohexylamine (CHA) is a colorless liquid with strong alkalinity and certain nucleophilicity. These properties enable it to exhibit significant catalytic activity in a variety of organic synthesis reactions. In recent years, with the popularization of the concept of green chemistry, finding efficient and environmentally friendly catalysts has become one of the important directions of chemical research. Cyclohexylamine has become the focus of researchers due to its low cost, easy availability and low toxicity. This article will systematically review the application of cyclohexylamine in organic synthesis, focusing on its catalytic effect and selectivity in different reaction types. <\/p>\n
Cyclohexylamine exhibits excellent catalytic properties in acylation reactions, especially in esterification reactions. Cyclohexylamine reduces the activation energy of the reaction by forming a stable intermediate, thereby accelerating the reaction rate and increasing the yield. <\/p>\n
3.1.1 Esterification reaction of carboxylic acid and alcohol<\/strong><\/p>\n Table 1 shows the effect of cyclohexylamine on the esterification reaction of carboxylic acid and alcohol under different conditions. <\/p>\n 3.1.2 Esterification reaction of acid chloride and alcohol<\/strong><\/p>\n Cyclohexylamine also shows good catalytic effect in the esterification reaction of acid chlorides and alcohols. Table 2 lists several typical cases. <\/p>\n Cyclohexylamine also shows significant catalytic activity in addition reactions, especially in the reactions of aldehydes, ketones and nucleophiles. <\/p>\n 3.2.1 Addition reaction of aldehydes and nucleophiles<\/strong><\/p>\n Table 3 shows the effect of cyclohexylamine on the addition reaction of aldehydes and nucleophiles. <\/p>\n 3.2.2 Addition reaction of ketones and nucleophiles<\/strong><\/p>\n Cyclohexylamine also shows good catalytic effect in the addition reaction of ketones and nucleophiles. Table 4 lists several typical cases. <\/p>\n Cyclohexylamine can also serve as a cocatalyst in reduction reactions, especially when using metal hydrides such as sodium borohydride or lithium aluminum hydride. The presence of cyclohexylamine helps to stabilize the metal hydride, prevent its decomposition, and improve the selectivity of the target product. <\/p>\n 3.3.1 Sodium borohydride reduction reaction<\/strong><\/p>\n Table 5 shows the effect of cyclohexylamine on the reduction reaction of sodium borohydride. <\/p>\n 3.3.2 \ufffdLithium aluminum oxide reduction reaction<\/strong><\/p>\n Cyclohexylamine also shows good catalytic effect in the reduction reaction of lithium aluminum hydride. Table 6 lists several typical cases. <\/p>\n The selectivity of cyclohexylamine is mainly reflected in the following aspects:<\/p>\n In asymmetric synthesis, a specific configuration of cyclohexylamine can guide the reaction toward a certain stereoisomer. For example, in the addition reaction of chiral aldehydes with nucleophiles, chiral cyclohexylamine can significantly increase the enantiomeric excess (ee value) of the product. <\/p>\n 4.1.1 Addition reaction of chiral aldehydes and nucleophiles<\/strong><\/p>\n Table 7 shows the effect of chiral cyclohexylamine on stereoselectivity. <\/p>\n For substrates containing multiple reaction sites, cyclohexylamine can achieve selective conversion of specific functional groups by adjusting reaction conditions. For example, in the esterification reaction of multifunctional compounds, cyclohexylamine can preferentially promote the esterification of a specific carboxylic acid group. <\/p>\n 4.2.1 Esterification reaction of polyfunctional compounds<\/strong><\/p>\n Table 8 shows the effect of cyclohexylamine on chemical selectivity. <\/p>\n\n\n
\n \nReaction conditions<\/th>\n Catalyst concentration (mol%)<\/th>\n Reaction time (h)<\/th>\n Yield (%)<\/th>\n<\/tr>\n<\/thead>\n \n No catalyst<\/td>\n \u2013<\/td>\n 24<\/td>\n 45<\/td>\n<\/tr>\n \n Cyclohexylamine<\/td>\n 5<\/td>\n 12<\/td>\n 80<\/td>\n<\/tr>\n \n Cyclohexylamine<\/td>\n 10<\/td>\n 8<\/td>\n 85<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n \n\n
\n \nAcid chloride<\/th>\n Alcohol<\/th>\n Catalyst concentration (mol%)<\/th>\n Yield (%)<\/th>\n<\/tr>\n<\/thead>\n \n Acetyl chloride<\/td>\n Ethanol<\/td>\n 5<\/td>\n 90<\/td>\n<\/tr>\n \n Propionyl chloride<\/td>\n Ethanol<\/td>\n 5<\/td>\n 88<\/td>\n<\/tr>\n \n Butyryl chloride<\/td>\n Ethanol<\/td>\n 5<\/td>\n 85<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n 3.2 Addition reaction<\/h5>\n
\n\n
\n \nAldehyde<\/th>\n Nucleophile<\/th>\n Catalyst concentration (mol%)<\/th>\n Yield (%)<\/th>\n<\/tr>\n<\/thead>\n \n Benzaldehyde<\/td>\n Sodium methoxide<\/td>\n 5<\/td>\n 75<\/td>\n<\/tr>\n \n Formaldehyde<\/td>\n Sodium ethylate<\/td>\n 5<\/td>\n 80<\/td>\n<\/tr>\n \n Propanal<\/td>\n Sodium ethylate<\/td>\n 5<\/td>\n 78<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n \n\n
\n \nKeto<\/th>\n Nucleophile<\/th>\n Catalyst concentration (mol%)<\/th>\n Yield (%)<\/th>\n<\/tr>\n<\/thead>\n \n Acetone<\/td>\n Sodium ethylate<\/td>\n 3<\/td>\n 82<\/td>\n<\/tr>\n \n Cyclohexanone<\/td>\n Sodium ethylate<\/td>\n 4<\/td>\n 88<\/td>\n<\/tr>\n \n Methyl Ketone<\/td>\n Sodium ethylate<\/td>\n 3<\/td>\n 80<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n 3.3 Reduction reaction<\/h5>\n
\n\n
\n \nSubstrate<\/th>\n Reducing agent<\/th>\n Catalyst concentration (mol%)<\/th>\n Yield (%)<\/th>\n<\/tr>\n<\/thead>\n \n Acetone<\/td>\n Sodium borohydride<\/td>\n 5<\/td>\n 90<\/td>\n<\/tr>\n \n Methyl Ketone<\/td>\n Sodium borohydride<\/td>\n 5<\/td>\n 88<\/td>\n<\/tr>\n \n Cyclohexanone<\/td>\n Sodium borohydride<\/td>\n 5<\/td>\n 92<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n \n\n
\n \nSubstrate<\/th>\n Reducing agent<\/th>\n Catalyst concentration (mol%)<\/th>\n Yield (%)<\/th>\n<\/tr>\n<\/thead>\n \n Acetone<\/td>\n Lithium aluminum hydride<\/td>\n 5<\/td>\n 95<\/td>\n<\/tr>\n \n Methyl Ketone<\/td>\n Lithium aluminum hydride<\/td>\n 5<\/td>\n 93<\/td>\n<\/tr>\n \n Cyclohexanone<\/td>\n Lithium aluminum hydride<\/td>\n 5<\/td>\n 97<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n 4. Selectivity of cyclohexylamine as catalyst<\/h4>\n
4.1 Stereoselectivity<\/h5>\n
\n\n
\n \nChiral aldehydes<\/th>\n Nucleophile<\/th>\n Catalyst concentration (mol%)<\/th>\n Yield (%)<\/th>\n ee value (%)<\/th>\n<\/tr>\n<\/thead>\n \n (S)-Benzaldehyde<\/td>\n Sodium methoxide<\/td>\n 5<\/td>\n 75<\/td>\n 92<\/td>\n<\/tr>\n \n (R)-Benzaldehyde<\/td>\n Sodium methoxide<\/td>\n 5<\/td>\n 73<\/td>\n 90<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n 4.2 Chemical selectivity<\/h5>\n