作者:Kui Zhang、Lingchao Cai、Zhongyue Yang、K. N. Houk、Ohyun Kwon
DOI:10.1039/c7sc04381c
日期:——
A novel bridged [2.2.1] bicyclic phosphineoxide, devised to circumvent the waste generation and burdens of purification that are typical of reactions driven by the generation of phosphineoxides, has been prepared in three steps from commercially available cyclopent-3-ene-1-carboxylic acid. The performance of this novel phosphineoxide was superior to those of current best-in-class counterparts, as
NHC-Catalyzed Aldol-Like Reactions of Allenoates with Isatins: Regiospecific Syntheses of γ-Functionalized Allenoates
作者:Sha Li、Ziwei Tang、Yang Wang、Dan Wang、Zhanlin Wang、Chenxia Yu、Tuanjie Li、Donghui Wei、Changsheng Yao
DOI:10.1021/acs.orglett.8b04082
日期:2019.3.1
carbene (NHC) catalyzed γ-specific aldol-like reaction between allenoates and isatins has been achieved under mild conditions, giving trisubstituted allene derivatives bearing isatin moiety in moderate to good yields with high diastereoselectivity and excellent atom efficiency. The DFT computations indicated that the formation of the γ-adduct was more energetically favorable than that of the α-adduct. The
Nickel-catalyzed, highly diastereoselective annulations between activated allenes and 2-acetylarylboronic acid or 2-formylarylboronic acids are reported. No ligand for nickel is required, and the reactions proceed efficiently at room temperature to give a broad range of substituted 3-methyleneindan-1-ols. Preliminary results of an enantioselective variant are also described.
Construction of adjacent spiro-quaternary and tertiary stereocenters through phosphine-catalyzed asymmetric [3+2] annulation of allenoates with alkylidene azlactones
作者:De Wang、Yin Wei、Min Shi
DOI:10.1039/c2cc17709a
日期:——
A novel axially chiral spiro-phosphine-catalyzed highly regio-, diastereo- and enantioselective [3+2] cycloaddition of alkylidene azlactones with various allenic esters has been developed, affording the corresponding functionalized spirocyclic products in moderate to excellent yields under mild conditions. These spirocyclic products as masked amino acids can be easily transformed into aspartic amino
Cationic Palladium-Catalyzed [5 + 2] Annulation of 2-Acylmethoxyarylboronic Acids and Allenoates: Synthesis of 1-Benzoxepine Derivatives
作者:Xufen Yu、Xiyan Lu
DOI:10.1021/jo200672w
日期:2011.8.5
The 1-benzoxepine derivatives were synthesized conveniently by cationicpalladium-catalyzed [5 + 2] annulation reaction of 2-acylmethoxyarylboronic acids with allenoates in high yields. This annulation involves the intramolecular nucleophilic addition to ketones without the formation of π-allylpalladium species.