- TMSOTf-mediated approach to 1,3-oxazin-2-one skeleton through one-pot successive reduction-[4 + 2] cyclization process of imides with ynamides
-
A one-pot approach to access functionalized 1,3-oxazin-2-one skeleton has been developed through successive reduction and subsequent [4 + 2] cyclization process of N-Boc lactams with ynamides by TMSOTf. As a result, a number of five to seven membered ring fused bicyclic [1,2-c][1,3]oxazin-1-ones 12a-m and tricyclic derivatives 13a-f were obtained in moderate to excellent yields with excellent regioselectivities. Moreover, linear N-Boc amides 9a-e were also amenable to this transformation, and the desired 3,4-dihydro-1,3-oxazin-2-ones 14a-m were readily achieved in moderate yields with excellent regioselectivities.
- Zhang, Chen-Chen,Huo, Zhi-Peng,Tang, Mei-Lin,Liang, Yong-Xi,Sun, Xun
-
supporting information
(2021/03/15)
-
- A Unified Strategy for the Synthesis of Difluoromethyl- And Vinylfluoride-Containing Scaffolds
-
Here, we report a general method for the synthesis of quaternary and tertiary difluoromethylated compounds and their vinylfluoride analogues. The strategy, which relies on a two-step sequence featuring a C-selective electrophilic difluoromethylation and either a palladium-catalyzed decarboxylative protonation or a Krapcho decarboxylation, is practical, scalable, and high yielding. Considering the generality of the method and the attractive properties offered by the difluoromethyl group, this approach provides a valuable tool for late-stage functionalization and drug development.
- Duchemin, Nicolas,Buccafusca, Roberto,Daumas, Marc,Ferey, Vincent,Arseniyadis, Stellios
-
supporting information
p. 8205 - 8210
(2019/10/16)
-
- N-Activated β-lactams as versatile reagents for acyl carrier protein labeling
-
Acyl carrier proteins are critical components of fatty acid and polyketide biosynthesis. Their primary function is to shuttle intermediates between active sites via a covalently bound phosphopantetheine arm. Small molecules capable of acylating this prosthetic group will provide a simple and reversible means of introducing novel functionality onto carrier protein domains. A series of N-activated β-lactams are prepared to examine site-specific acylation of the phosphopantetheine-thiol. In general, β-lactams are found to be significantly more reactive than our previously studied β-lactones. Selectivity for the holo over apo-form of acyl carrier proteins is demonstrated indicating that only the phosphopantetheine-thiol is modified. Incorporation of an N-propargyloxycarbonyl group provides an alkyne handle for conjugation to fluorophores and affinity labels. The utility of these groups for mechanistic interrogation of a critical step in polyketide biosynthesis is examined through comparison to traditional probes. In all, we expect the probes described in this study to serve as valuable and versatile tools for mechanistic interrogation.
- Prasad, Gitanjeli,Amoroso, Jon W.,Borketey, Lawrence S.,Schnarr, Nathan A.
-
experimental part
p. 1992 - 2002
(2012/04/23)
-
- Hydrozirconation of four-, five-, six- and seven-membered N-alkoxycarbonyl lactams to lactamols
-
A general, practical, and efficient reduction of four-, five-, six- and, seven-membered N-alkoxycarbonyl lactams to the aldehyde oxidation state is reported. The reduction methodology involves the hydrozirconation reaction by Cp2Zr(H)Cl under m
- Piperno, Anna,Carnovale, Caterina,Giofr, Salvatore V.,Iannazzo, Daniela
-
supporting information; experimental part
p. 6880 - 6882
(2012/02/05)
-
- Enzymatic synthesis of carnosine derivatives catalysed by Burkholderia cepacia lipase
-
A new enzymatic synthesis of α,β-dipeptides has been developed with particular focus on the preparation of carnosine (β-alanyl-α-histidine) and analogues. The lipase PS-D from Burkholderia cepacia has been used as a catalyst for the formation of the pepti
- D'Arrigo, Paola,Kanerva, Liisa T.,Li, Xiang-Guo,Saraceno, Caterina,Servi, Stefano,Tessaro, Davide
-
experimental part
p. 1641 - 1645
(2009/12/04)
-
- Hydrogenation of N-acylcarbamates and N-acylsulfonamides catalyzed by a bifunctional [Cp*Ru(PN)] complex
-
Awakening of the Cp one: the bifunctional complex 1 facilitates the interaction with substrates bearing less electrophilic carbon atoms than ketones, epoxides, and imides. The title reaction was applicable to the reduction of Evans' asymmetric alkylation products to the chiral alcohols along with gtood recovery of the chiral oxazolidinone auxiliary. EWG=electron- withdrawing group.
- Ito, Masato,Koo, Lee Wei,Himizu, Akio,Kobayashi, Chika,Sakaguchi, Ayaka,Ikariya, Takao
-
supporting information; experimental part
p. 1324 - 1327
(2009/06/30)
-
