What happens to reaction of using ethanol as a solvent and replacing it with the liquor you drink

Scientists at The Scripps Research Institute (TSRI) have invented a new way to couple complex organic molecules and synthesized more than 60 new compounds, 90% of which are new chemical entities (NCEs)—the new Chemical entities have previously appeared to either lack the practical conditions for synthesis or to be impossible to synthesize at all. This research on the cross-coupling of carboxyl-functional olefins was published in the December 17th issue of the journal Nature (Title: Functionalized olefin cross-coupling to construct carbon–carbon bonds, Nature, 516, 343-348, DOI: 10.1038 /nature14006).

In order to prove the practicality of this reaction, the author made a bold attempt to replace the organic solvent with daily alcoholic beverages. Ethanol was used as the control group A, group B was vodka, group C was tequila, group D was Seagram gin, group E was whisky, group F was boulder IPA, group G was chardonnay and group H It is Monteth Merlot Red.

In fact, from the results of TLC, group C is agave, group F is boulder IPA, and group H is Monteth Merlot red. Compared with other groups, the proportion of products obtained is less and the effect is poor. And group D is Shigeland gin, and group E is whisky as a reaction solvent, and more C-C coupling products are obtained. The editor guesses that whisky and Shigeland have more alcohol content and purity. higher.

Using the new technique, researchers can couple two olefins and create new chemical bonds on their carbon atom backbones. The new method is called the "gentle method," meaning it doesn't require extreme temperatures and pressures, or harsh chemicals, according to the Physicists Network. Therefore, functional groups that would be disrupted using other cross-coupling methods can be chemically "untouched" in this new method. At the same time, the requirements for the experimental equipment of the new method are also very simple. It only needs to use ordinary iron catalysts and use silane and ethanol that are common in the market as solvents, and the experiment can be carried out in an open flask, that is to say, there is no need to exclude air. and moisture.

The carbon-carbon coupling method has an important place in the synthesis of organic compounds, but so far this method has been plagued by its limitations: if one of the starting compounds contains a functional group attached to its host structure, experiments often end in failure ; and in the presence of "heteroatoms"—non-carbon atoms such as nitrogen, oxygen, and iodine, etc.—this method often does not work well, even though these "heteroatoms" are important in chemical synthesis.

The new discovery stems from a research project at the Scripps Research Institute on the synthesis of natural compounds in traditional Chinese medicine. In this project, the research team developed a technique for making target molecules in the laboratory. They then realized that the new technique could be used to couple two simpler alkenes. The next step will be to refine the technique for more complex coupling of olefins attached to "heteroatoms."

Building on previous experiments, the authors used the model system shown in Figure 2a with silyl enol ether 1 as the donor and cyclohexenone (2) as the acceptor to form functionalized olefin cross-couplings. These conditions were similar to those developed previously, employing Fe(ACAC) 3 (4, ACAC, acetylacetone) as catalyst and PhSiH as stoichiometric reducing agent. The reductive coupling product 3 was formed in 53% yield based on GC/MS (gas chromatography/mass spectrometry) using an internal standard. Analysis of by-products in the model system and related reactions resulted in the production of by-products 14–17 (Fig. 2b).

Compounds 16 and 17 may be derived from the property of Fe(acac)3 to behave as a Lewis acid, and the authors hope to weaken the Lewis acidity of the catalyst by increasing the amount of steric shielding of the Fe center. Although attempts to alter the electronic structure of the ligand with electron-deficient (10 and 11) and electron-rich (12 and 13) substituents eliminated the reactivity, the addition of Na2HPO4 increased the yield of the desired product 3 from 69% when Fe was used When (dibm)3 was used as a catalyst, it reached 78%. The use of about 45 other inorganic and amine bases as additives did not result in an increase in yield, indicating that Na2HPO4 does more than act as a buffer. In addition, Fe(dibm)3 was able to form products with donors that did not react with Fe(acac)3 (18, Fig. 2c), which instead provided substantial by-products 16 and 17. In the course of this experiment, the authors found that Fe(dibm)3 heteroatom substitutions on the donor olefins provided the highest yields when they contained a Lewis basic lone pair, whereas Fe(acac)3 gave the highest yields in the absence of such moieties The following proves to be excellent.