Synthesis of sterically hindered enamides via a Ti-mediated condensation of amides with aldehydes and ketones.
نویسندگان
چکیده
The first TiCl(4)-mediated condensation of secondary amides with aldehydes and ketones has been achieved. The reaction proceeds at room temperature and is complete within 5 h in most cases. The optimized procedure used 5 equiv of an amine base hinting that the in situ activation of both the amide and the Lewis acid is required. The reaction affords polysubstituted (E)-enamides.
منابع مشابه
New Synthetic Technology for the Mild and Selective One-Carbon Homologation of Hindered Aldehydes in the Presence of Ketones.
A selective, mild, and highly efficient method has been uncovered during the total synthesis of the CP molecules to accomplish the one-carbon homologation of sterically hindered aldehydes in the presence of acid- and base-labile moieties, Michael acceptors, and even other carbonyl groups such as reactive and epimerizable ketones. Mechanistic studies have revealed a neutral reagent for the rapid...
متن کاملFormation of amides: one-pot condensation of carboxylic acids and amines mediated by TiCl4
A general procedure for the synthesis of amides via the direct condensation of carboxylic acids and amines in the presence of TiCl4 is reported. The amidation reaction was performed in pyridine at 85 °C with a wide range of substrates providing the corresponding amide products in moderate to excellent yields and high purity. The reaction proceeds with low yields when both the carboxylic acid an...
متن کاملA Convenient Base-Mediated Diastereoselective Synthesis of 2-Oxo-N,4,6-triarylcyclohex-3-enecarboxamides via Claisen-Schmidt Condensation
Sodium acetate catalyzed the multi-component reaction of acetophenone, aromatic aldehydes, and acetoacetanilide in the water-ethanol mixture (1:1) at ambient temperature via Claisen-Schmidt condensation results in the formation of highly substituted cyclohexenones in 89–98% yields. The developed efficient catalytic approach to the substituted cyclohexenones – the promising ...
متن کاملApplication of a Polymer-Bound Thiazolium Salt to the Synthesis of Alpha-Hydroxy Ketones with an Aromatic and Aliphatic Substituent (Bencyloins) [1]
Alpha-Hydroxy ketones with an aromatic and aliphatic substituent were prepared with condensation of aromatic and aliphatic aldehydes in the presence of polymer-bound thiazolium salt.
متن کاملGeneral Route for Preparing β-Nitrocarbonyl Compounds Using Copper Thermal Redox Catalysis
Using a simple copper catalyst, the alkylation of nitroalkanes with α-bromocarbonyls is now possible. This method provides a general, functional group tolerant route to β-nitrocarbonyl compounds, including nitro amides, esters, ketones, and aldehydes. The highly sterically dense, functional group rich products from these reactions can be readily elaborated into a range of complex nitrogen-conta...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Chemical communications
دوره 48 53 شماره
صفحات -
تاریخ انتشار 2012