Various aromatic and heterocyclic oxazolines were directly converted to respective cyanomethyl esters with pyridinium hydrobromide perbromide in water at room temperature.
Titanium-Mediated Addition of Grignard Reagents to Acyl Cyanohydrins: Aminocyclopropane versus 1,4-Diketone Formation
作者:Paul Setzer、Gwénaël Forcher、Fabien Boeda、Morwenna S. M. Pearson-Long、Philippe Bertus
DOI:10.1002/ejoc.201301251
日期:2014.1
The 1,2-dianion reactivity of the reagent generated from EtMgBr and titanium isopropoxide was illustrated when N-acyl cyanohydrins were used as substrates (>20 examples), giving both aminocyclopropane derivatives and 1,4-dicarbonyl compounds. When the reaction was performed in diethyl ether, 5-hydroxy-1,4-diketones were the main product. Under specific conditions (use of tetrahydrofuran and a bulky
The first oxidativecoupling of alkylnitriles with aromatic carboxylicacids using di-tert-butyl peroxide (DTBP) as oxidant was achieved under the catalysis of ionic Fe(III) complexes bearing an imidazolinium cation. This protocol features nontoxic iron catalysis, direct α-C(sp3)–H bond oxidative esterification of alkylnitriles, non-prefunctionalized starting materials, and a broad substrate scope
Cyanoacetic Acid as a Masked Electrophile: Transition-Metal-Free Cyanomethylation of Amines and Carboxylic Acids
作者:Hongxiang Wang、Ying Shao、Hao Zheng、Hanghang Wang、Jiang Cheng、Xiaobing Wan
DOI:10.1002/chem.201502733
日期:2015.12.7
Using cyanoaceticacid as a maskedelectrophile, a new cyanomethylation reaction of amines and carboxylicacids was developed, producing a variety of α‐aminonitriles and cyanomethyl esters with good yields and excellent functionality tolerance. This protocol features simple manipulation, inexpensive reagents, and a wide substrate scope. Iodoacetonitrile was generated in situ from the iodination–decarboxylation
Titanium-Mediated Synthesis of 1,4-Diketones from Grignard Reagents and Acyl Cyanohydrins
作者:Paul Setzer、Alice Beauseigneur、Morwenna S. M. Pearson-Long、Philippe Bertus
DOI:10.1002/anie.201003923
日期:2010.11.8
Double duty: In the presence of titanium isopropoxide, Grignard reagents were found to react with acyl cyanohydrins to give substituted 5‐hydroxy‐1,4‐diketones (see scheme). This new reaction involves a formal addition of a 1,2‐dianionequivalent to both the ester and nitrile moieties.
A palladium‐catalyzed tandem reaction of cyanomethyl benzoates with arylboronic acids has been achieved. Substitution at the 2‐position of cyanomethyl benzoates was found to be crucial for the selective synthesis of oxazoles and isocoumarins. Cyanomethyl benzoates afforded 2,4‐diaryloxazoles as products, while 2‐benzoyl‐substituted cyanomethyl benzoates delivered 3‐benzoyl‐4‐aryl‐isocoumarins selectively