79248-52-5Relevant academic research and scientific papers
A lewis acid-promoted pinner reaction
Pfaff, Dominik,Nemecek, Gregor,Podlech, Joachim
supporting information, p. 1572 - 1577 (2013/10/22)
Carbonitriles and alcohols react in a Lewis acid-promoted Pinner reaction to carboxylic esters. Best results are obtained with two equivalents of trimethylsilyl triflate as Lewis acid. Good yields are achieved with primary alcohols and aliphatic or benzylic carbonitriles, but the straightforward synthesis of acrylates and benzoates starting with acrylonitrile and benzonitrile, respectively, is similarly possible. Phenols are not acylated under these reaction conditions. The method has been used for the first total synthesis of the natural product monaspilosin. In the reaction of benzyl alcohols variable amounts of amides are formed in a Ritter-type side reaction.
Benzyloxy(4-substituted benzyloxy)carbenes. Generation from oxadiazolines and fragmentation to radical pairs in solution
Merkley,Warkentin
, p. 942 - 949 (2007/10/03)
Thermolysis of 2,2-dibenzyloxy-5,5-dimethyl-Δ3-1,3,4-oxadiazoline in benzene at 110°C leads to dibenzyloxycarbene. The carbene was trapped with tert-butyl alcohol to afford dibenzyl-tert-butyl orthoformate. In the absence of a trapping agent for the carbene, it fragmented to benzyloxycarbonyl and benzyl radicals, as shown by trapping the latter with TEMPO. In the absence of both TEMPO and tert-butyl alcohol, the radicals were partitioned between coupling to benzyl phenylacetate and decarboxylation, with subsequent formation of bibenzyl. The preferred sense of fragmentation of the analogous carbenes from benzyloxy-(p-substituted-benzyloxy)carbenes was determined by comparing the yields of the two possible esters, ArCH2O(CO)CH2Ph and PhCH2O(CO)CH2Ar. It was found that an electron-withdrawing group in the para position favoured fragmentation to the benzylic radical containing that group. A Hammett plot of the data gave a best fit with σ- substituent constants (r = 0.994, ρ((PhH, 110°C) = 0.7)) suggesting that the fragmentation involves charge separation in the sense that increases electron density on the group that is becoming a benzylic radical and decreases electron density on the carbonyl group that is becoming the benzyloxycarbonyl radical.
Synthesis of esters from acyl chlorides and halide under solid-liquid phase transfer catalysis
Hu,Pa,Cui,Wang
, p. 2763 - 2767 (2007/10/02)
A new and general method for the synthesis of esters is reported. Acyl chloride reacts with halide in the presence of hydrogen carbonate and under solid-liquid phase transfer condition to afford the esters in good to excellent isolated yields. The effects of catalyst, sodium and solvents to the reactions have been investigated. The reaction mechanism is briefly discussed.
