Cu-Catalyzed asymmetric addition of alcohols to β,γ-alkynyl-α-imino esters for the construction of linear chiral N,O-ketals was written by Sheng, Cheng;Ling, Zheng;Luo, Yicong;Zhang, Wanbin. And the article was included in Nature Communications in 2022.Quality Control of 2-Ethynylthiophene This article mentions the following:
Herein, a Cu-catalyzed asym. addition of alcs. to β,γ-alkynyl-α-imino esters was developed under mild conditions, providing the corresponding linear chiral N,O-ketals I [R1 = n-Bu, Ph, 2-thienyl, etc.; R2 = Me, Et, n-Pr, n-Bu; R3 = Me, Et, cyclobutyl, Bn, etc.] with up to 96% ee. The method tolerated some variation in the β,γ-alkynyl-α-imino esters and alc. scope, including some glucose and natural amino acid derivatives Computational results indicated that the Boc group of the substrates assist in the extraction of hydrogen atoms from the alcs. to promote the addition reactions. These products could be synthesized on a gram-scale and can be used in several transformations. This asym. addition system provided an efficient, mild, gram-scale, and transition-metal-catalyzed synthesis of linear chiral N,O-ketals. In the experiment, the researchers used many compounds, for example, 2-Ethynylthiophene (cas: 4298-52-6Quality Control of 2-Ethynylthiophene).
2-Ethynylthiophene (cas: 4298-52-6) belongs to benzothiophene derivatives. Benzothiophene is a fused ring compound of thiophene ring and benzene ring, which is an important class of heterocycles with advantageous structures. It is found within the chemical structures of pharmaceutical drugs such as zileuton, raloxifene, and sertaconazole, and also BTCP.Quality Control of 2-Ethynylthiophene
Referemce:
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem