28172-53-4Relevant academic research and scientific papers
Catalytic Aerobic Cross-Dehydrogenative Coupling of Azlactones en Route to α,α-Disubstituted α-Amino Acids
Tsuji, Taro,Tanaka, Takafumi,Tanaka, Tsukushi,Yazaki, Ryo,Ohshima, Takashi
supporting information, p. 4164 - 4170 (2020/06/04)
We developed a catalytic aerobic method to synthesize α,α-disubstituted α-amino acids through cross-dehydrogenative coupling of azlactones. Combining an iron catalyst with a bisoxazolidine ligand resulted in high catalytic performance, and cross-coupling with an indole proceeded smoothly under aerobic conditions. A wide variety of α-aryl and aliphatic amino acid derived azlactones were applied to the present catalysis. In addition, a quaternary carbon could be constructed using oxindole and benzofuranone under aerobic conditions.
Regiodivergent Enantioselective γ-Additions of Oxazolones to 2,3-Butadienoates Catalyzed by Phosphines: Synthesis of α,α-Disubstituted α-Amino Acids and N,O-Acetal Derivatives
Wang, Tianli,Yu, Zhaoyuan,Hoon, Ding Long,Phee, Claire Yan,Lan, Yu,Lu, Yixin
, p. 265 - 271 (2016/01/25)
Phosphine-catalyzed regiodivergent enantioselective C-2- and C-4-selective γ-additions of oxazolones to 2,3-butadienoates have been developed. The C-4-selective γ-addition of oxazolones occurred in a highly enantioselective manner when 2-aryl-4-alkyloxazol-5-(4H)-ones were employed as pronucleophiles. With the employment of 2-alkyl-4-aryloxazol-5-(4H)-ones as the donor, C-2-selective γ-addition of oxazolones took place in a highly enantioselective manner. The C-4-selective adducts provided rapid access to optically enriched α,α-disubstituted α-amino acid derivatives, and the C-2-selective products led to facile synthesis of chiral N,O-acetals and γ-lactols. Theoretical studies via DFT calculations suggested that the origin of the observed regioselectivity was due to the distortion energy that resulted from the interaction between the nucleophilic oxazolide and the electrophilic phosphonium intermediate.
Inhibition of the human proteasome by imidazoline scaffolds
Azevedo, Lauren M.,Lansdell, Theresa A.,Ludwig, Jacob R.,Mosey, Robert A.,Woloch, Daljinder K.,Cogan, Dillon P.,Patten, Gregory P.,Kuszpit, Michael R.,Fisk, Jason S.,Tepe, Jetze J.
supporting information, p. 5974 - 5978 (2013/08/23)
The proteasome has emerged as the primary target for the treatment of multiple myeloma. Unfortunately, nearly all patients develop resistance to competitive-type proteasome inhibitors such as bortezomib. Herein, we describe the optimization of noncompetit
Synthesis of di- and tri-substituted imidazole-4-carboxylates via PBu3-mediated [3+2] cycloaddition
Hsu, Mei-Yuan,Dietrich, Justin,Hulme, Christopher,Shaw, Arthur Y.
, p. 1538 - 1542 (2013/05/21)
Some new di- and trisubstituted imidazole-4-carboxylates were prepared from amidoacetic acids 3 in the present report. The key step to establish such imidazole- 4-carboxylates stemmed from the PBu3-mediated [3+2] cycloaddition between in situ-generated Δ2-oxazolinone 4 and ethyl cyanoformate6. Our results indicated that trisubstituted imidazoles 7-20 were afforded in better yields than those of disubstituted imidazoles 21-27. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications1 to view the free supplemental file. Copyright Taylor & Francis Group, LLC.
