A novel metal-free direct addition of molecular oxygen to the C–C triple bond toward benzannulated oxygen-bridged seven-membered ring systems and aza[3.1.0]bicycleskeletons under 3O2 atmosphere has been described. The reaction proceeds through at least three intramolecular C–O and C–C bond forming steps via green, simple, and unprecedented domino radical processes with high selectivity and good yields
已经描述了在3 O 2气氛下向C-C三键向苯环的氧桥联的七元环系统和aza [3.1.0]自行车骨架的无氧金属新的无金属直接加成。该反应至少通过三个分子内C–O和C–C键形成步骤,通过绿色,简单且前所未有的多米诺基自由基工艺进行,具有高选择性和高收率。
A novel iodine-mediated tandem cyclization–cycloaddition reaction leading to polyoxacyclic ring systems
A novel iodine-catalyzed tandem cyclization-cycloaddition reaction of ortho-alkynyl-substituted benzaldehydes leading to polyoxacyclic ring systems has been developed, which represents a useful approach towards the synthesis of the oxabicyclo-[3.2.1]octane ring skeleton found in a variety of natural products.
Intramolecular Carboxyamidation of Alkyne‐Tethered <i>O</i>‐Acylhydroxamates through Formation of Fe(III)‐Nitrenoids
作者:Siyuan Su、Yu Zhang、Peng Liu、Donald J. Wink、Daesung Lee
DOI:10.1002/chem.202303428
日期:2024.1.26
induced spontaneous or 4-(dimethylamino)pyridine-catalyzed O→O or O→N acyl group migration can generate a wide variety of N,O-containing heterocycles. DFT study suggests the Fe-nitrenoid intermediate preferentially reacts in a radical manifold to mediates a stepwise C−N/C−O bond formation rather than a concerted [3+2] cycloaddition mechanism.
Zip and shift : 炔烃束缚的O-酰基异羟肟酸酯的分子内羧酰胺化,然后是热诱导自发或4-(二甲氨基)吡啶催化的O→O或O→N酰基迁移,可以生成多种含N 、 O的杂环。 DFT 研究表明,Fe-氮烯类中间体优先在自由基流形中反应,介导逐步的 C−N/C−O 键形成,而不是协调一致的 [3+2] 环加成机制。
Reactivity of Enyne-Allenes Generated via an Alder-Ene Reaction
作者:Duy-Viet Vo、Siyuan Su、Rajdip Karmakar、Daesung Lee
DOI:10.1021/acs.orglett.3c03696
日期:2024.2.23
Tandem transformations of 1,3-diynyl propiolate derivatives are described. The Alder-ene reaction generates an enyne-allene, which undergoes a formal 1,7-H shift or a Diels–Alder reaction, depending on the substituent on the alkyne. A terminal or aryl-substituted alkyne promotes a 1,7-H shift to generate a new enyne-allene, which undergoes a Myers–Saito cycloaromatization followed by a 1,5-H transfer-mediated