4219-24-3Relevant articles and documents
Iridium-Catalyzed γ-Selective Hydroboration of γ-Substituted Allylic Amides
Zhao, Hongliang,Gao, Qian,Zhang, Yajuan,Zhang, Panke,Xu, Senmiao
supporting information, p. 2861 - 2866 (2020/04/02)
Reported here for the first time is the Ir-catalyzed γ-selective hydroboration of γ-substituted allylic amides under mild reaction conditions. A variety of functional groups could be compatible with reaction conditions, affording γ-branched amides in good yields with ≤97% γ-selectivity. We have also demonstrated that the obtained borylated products could be used in a series of C-O, C-F, C-Br, and C-C bond-forming reactions.
A practical copper-catalyzed approach to β-lactams: via radical carboamination of alkenyl carbonyl compounds
Shi, Peng,Wang, Jie,Gan, Zixu,Zhang, Jingyu,Zeng, Runsheng,Zhao, Yingsheng
supporting information, p. 10523 - 10526 (2019/09/06)
Functionalized β-lactams are highly important motifs in synthetic chemistry. We report an efficient and novel approach to the synthesis of β-lactams via a copper(i)-catalyzed cascade process involving C(benzyl)-H radical abstraction, intermolecular alkene addition, and intramolecular amination reaction. Variously substituted alkenes were synthesized from vinylacetic acid, leading to the corresponding β-lactams in moderate to good yields. Preliminary studies indicate that the reaction undergoes a free radical mechanism via a Cu(i)/Cu(ii)/Cu(iii) catalytic cycle.
Stereoselective Synthesis of Highly Substituted Tetrahydropyrans through an Evans Aldol-Prins Strategy
álvarez-Méndez, Sergio J.,Fari?a-Ramos, Marta,Villalba, María Luisa,Perretti, Marcelle D.,García, Celina,Moujir, Laila M.,Ramírez, Miguel A.,Martín, Víctor S.
, p. 9039 - 9066 (2018/08/06)
A direct and general method for the synthesis of naturally occurring 2,3,4,5,6-pentasubstituted tetrahydropyrans has been developed, employing β,γ-unsaturated N-acyl oxazolidin-2-ones as key starting materials. The combination of the Evans aldol addition and the Prins cyclization allowed the diastereoselective and efficient generation of the desired oxacycles in two fashions: a one-pot Evans aldol-Prins protocol, in which five new σ bonds and five contiguous stereocenters were straightforwardly generated, and a two-step version, which additionally permitted the isolation of β,γ-unsaturated alcohol precursors bearing an N-acyl oxazolidin-2-one in the α position. From these alcohols were also obtained halogenated pentasubstituted tetrahydropyrans as well as 2,3,4,5-tetrasubstituted tetrahydrofurans, shedding light on the mechanism of the process. Computational studies were consistent with the experimental findings, and this innovative Evans aldol-Prins strategy was performed for the preparation of a battery of more than 30 densely substituted tetrahydropyrans, unprecedentedly fused to a 1,3-oxazinane-2,4-dione ring, both in a racemic fashion and in an enantiomeric fashion. These novel molecules were successfully submitted to several transformations to permit simple access to a variety of differently functionalized tetrahydropyrans. Most of these unique molecules were evaluated for their antimicrobial activity against Gram-positive and Gram-negative bacteria and the yeast Candida albicans, and some structure-activity relationships were established.