38968-65-9Relevant academic research and scientific papers
Synergistic Peptide and Gold Catalysis: Enantioselective Addition of Branched Aldehydes to Allenamides
Nicholls, Leo D. M.,Wennemers, Helma
, p. 17559 - 17564 (2021/10/19)
The combination of a peptide catalyst and a gold catalyst is presented for enantioselective addition reactions between branched aldehydes and allenamides. The two catalysts act in concert to provide γ,δ-enamide aldehydes bearing a fully substituted, benzylic stereogenic center – a structural motif common in many natural products and therapeutically active compounds – with good yields and enantioselectivities. The reaction tolerates a variety of alkyl and alkoxy substituted aldehydes and the products can be elaborated into several chiral building blocks bearing either 1,4- or 1,5- functional group relationships. Mechanistic studies showed that the conformational features of the peptide are important for both the catalytic efficiency and stereochemistry, while a balance of acid/base additives is key for ensuring formation of the desired product over undesired side reactions.
Facile synthesis of α-alkoxyl amides: Via scandium-catalyzed oxidative reaction between ynamides and alcohols
Zhang, Zhi-Xin,Zhu, Bo-Han,Xie, Pei-Xi,Tang, Jia-Qi,Li, Xin-Ling,Zhu, Chunyin,Yin, Ying-Wu,Ye, Long-Wu
, p. 18308 - 18315 (2018/05/30)
A novel and efficient scandium-catalyzed oxidative reaction between ynamides and alcohols for the facile synthesis of various α-alkoxyl amides is reported in this paper. The reaction avoids the need for the use of α-diazo carbonyls which are unstable and
Aniline mediated oxidative C-C bond cleavage of α-alkoxy aldehydes in air and a model reaction for the synthesis of α-(d)-amino acid derivatives
Hu, Bin,Li, Yunfeng,Li, Zhongjun,Meng, Xiangbao
supporting information, p. 4138 - 4141 (2013/07/05)
A metal-free and 4-methyl aniline mediated method for the oxidative C-C bond cleavage has been developed. The reaction proceeds in air using molecular oxygen as the oxidant, affording one-carbon shortened esters in moderate to good yields within a short time. Moreover, it provides a model reaction for the highly enantioselective synthesis of (d)-serine esters by combining with a l-proline catalyzed Mannich reaction.
α-Aroyloxyaldehydes: Scope and limitations as alternatives to α-haloaldehydes for NHC-catalysed redox transformations
Ling, Kenneth B.,Smith, Andrew D.
experimental part, p. 373 - 375 (2011/02/24)
α-Aroyloxyaldehydes are readily prepared bench stable synthetic intermediates. Their ability to act as α-haloaldehyde surrogates for NHC-promoted redox esterifications and in [4+2] cycloadditions is described.
Remote substituent effect favoring the formation of syn-adducts in the chelation controlled radical reactions of γ-benzyloxy-α-methylenecarboxylic acid esters
Nagano, Hajime,Ohkouchi, Hisako,Yajima, Tomoko
, p. 3649 - 3663 (2007/10/03)
The chelation controlled radical reactions of ethyl γ-benzyloxy-α-methylenecarboxylates bearing a bulky γ-substituent, such as CHMe2, CHPh2, c-C6H11 and CH(Ph)OTBDMS, with alkyl iodides gave the syn-adducts with high diastereoselectivities. However, the diastereoselectivity for the substrates bearing a γ-substituent CH(i-Pr)OTBDMS depended critically on the configuration of the substituent; the substrate bearing the OTBDMS group anti to the γ-benzyloxy group showed poor diastereoselectivity, but its diastereomer gave syn-adduct exclusively. The high syn-selectivitiy is referred to the H-atom transfer to the outside face of radical center in the sharply folded seven-membered chelate intermediate bearing the ethoxy group with Z-geometry. The corner flapping of the radical center atom of the global minimum energy conformer generates a local minimum conformer and the H-atom transfer to the outside face of the radical center of the newly formed structure gives the anti-adduct. The poor diastereoselectivity is due to the very small energy difference between the two conformers and consequently both the syn- and anti-adducts are yielded in nearly equal amounts.
Diastereoselectivity of the conjugate addition of organocopper reagents to γ-alkoxy α,β-unsaturated carbonyl derivatives. Importance of the reagent type and the double-bond geometry
Yamamoto, Yoshinori,Chounan, Yukiyasu,Nishii, Shinji,Ibuka, Toshiro,Kitahara, Haruo
, p. 7652 - 7660 (2007/10/02)
Systematic investigations of the diastereoselectivity of organocopper conjugate addition to γ-alkoxy trans enoates (3), cis enoates (4), and diesters (5) revealed that the selectivity highly depended on the substrate structure and the reagent type. The an
