Brønsted Acid Catalyzed Dearomatization by Intramolecular Hydroalkoxylation/Claisen Rearrangement: Diastereo‐ and Enantioselective Synthesis of Spirolactams
作者:Peng‐Fei Chen、Bo Zhou、Peng Wu、Binju Wang、Long‐Wu Ye
DOI:10.1002/anie.202113464
日期:2021.12.20
A Brønstedacidcatalyzedintramolecular hydroalkoxylation/Claisen rearrangement is disclosed that involves an unexpected dearomatization of nonactivated arenes and heteroaromatic compounds and allows the practical and atom-economic synthesis of various valuable spirolactams. Moreover, the asymmetric version of this tandem cyclization is also achieved via kinetic resolution by chiral phosphoric acid
N-Alkynylated sulfoximines have been obtained by copper-catalyzed cross-coupling reactions starting from NH-sulfoximines and bromoacetylenes in moderate to good yields. The reaction conditions are mild, and the substrate scope is wide.
Gold(<scp>iii</scp>)-catalyzed chemoselective annulations of anthranils with <i>N</i>-allylynamides for the synthesis of 3-azabicyclo[3.1.0]hexan-2-imines
作者:Lina Song、Xianhai Tian、Matthias Rudolph、Frank Rominger、A. Stephen K. Hashmi
DOI:10.1039/c9cc04027g
日期:——
We herein report the gold(iii)-catalyzed selective annulation of anthranils with N-allylynamides under mild conditions.
我们在此报告了在温和条件下金(III)催化的选择性闭环反应,即苯并噻唑与N-烯丙基亚胺的环化。
Highly Efficient Synthesis of<i>α</i>-Halomethylketones via Ce(SO<sub>4</sub>)<sub>2</sub>/Acid Co-Catalyzed Hydration of Alkynes
A general atom‐economical approach for the synthesis of α‐halomethyl ketones is demonstrated through Ce(SO4)2/acid co‐catalyzed hydration of a wide range of haloalkynes. The reactions are conducted under convenient conditions and provide products with excellent regioselectivity in good to excellent yields, with broad substrate scope. This protocol is an alternative to conventional α‐halogenation of
Sunlight-Driven Decarboxylative Alkynylation of α-Keto Acids with Bromoacetylenes by Hypervalent Iodine Reagent Catalysis: A Facile Approach to Ynones
作者:Hui Tan、Hongji Li、Wangqin Ji、Lei Wang
DOI:10.1002/anie.201503479
日期:2015.7.13
A novel and practical decarboxylativealkynylation of α‐keto acids with bromoacetylenes is catalyzed by hypervalent iodine(III) reagents when irradiation by sunlight at room temperature. The product ynones are generated in good yields. Experiments show that results obtained with blue light (λ=450–455 nm) are comparable to those obtained when using sunlight. Mechanistic studies demonstrate that the