The Divergent Cascade Reactions of Arylalkynols with Homopropargylic Amines or Electron-Deficient Olefins: Access to the Spiro-Isobenzofuran-<i>b</i>-pyrroloquinolines or Bridged-Isobenzofuran Polycycles
作者:Lun Wang、Lingyan Liu、Weixing Chang、Jing Li
DOI:10.1021/acs.joc.8b00691
日期:2018.8.3
Two divergent cascade reactions of arylalkynols with homopropargylic amines or electron-deficient olefins were developed to synthesize the spiro-isobenzofuran-b-pyrroloquinolines or bridged-isobenzofuran heterocycles in good yields, respectively. One reaction actually involved intramolecular 5-endo-dig hydroamination cyclization–protonation of homopropargylic amines to give cycloiminium ions and intramolecular
α-bromocarbonyls for the synthesis of various cyclohexenone-fused polycyclic compounds is described. Up to six new C–C bonds and four new carbocycles can be established in a single reaction, highlighting the high efficiency and step-economics of this protocol. This reaction offers a novel and straightforward entry to the synthesis of ketones featuring the addition of carbon radicals to aldehydes.
Palladium-Catalyzed Aminomethylative Oppolzer-Type Cyclization of Enynes: Access to Aminomethylated Benzofulvenes
作者:Renbin Huang、Bangkui Yu、Renren Li、Hanmin Huang
DOI:10.1021/acs.orglett.1c03720
日期:2021.12.17
A novel palladium-catalyzed Oppolzer-type cyclization reaction aided by the aminomethyl cyclopalladated complex has been developed, which provides rapid access to functionalized benzofulvenes with excellent stereoselectivity. The corresponding products can undergo Diels–Alder reaction with maleimides, providing a series of complex polycyclic compounds with excellent regio- and stereoselectivities.
A catalytic [1,3] O‐to‐C rearrangement from enyne‐ethers was developed for the rapid synthesis of diverse bridged bicyclic systems. In this reaction, a vinyl oxonium intermediate, generated in situ from enyne‐ether, was the precursor for the [1,3] O‐to‐C rearrangement. This versatile protocol represents the first example of catalytic [1,3] O‐to‐C rearrangement based on ring‐expansion strategy, enabling
C,O-Chelated BINOL/Gold(III) Complexes: Synthesis and Catalysis with Tunable Product Profiles
作者:Jian-Fang Cui、Hok-Ming Ko、Ka-Pan Shing、Jie-Ren Deng、Nathanael Chun-Him Lai、Man-Kin Wong
DOI:10.1002/anie.201612243
日期:2017.3.6
Unprecedented stable BINOL/gold(III) complexes, adopting a novel C,O‐chelation mode, were synthesized by a modular approach through combination of 1,1′‐binaphthalene‐2,2′‐diols (BINOLs) and cyclometalated gold(III) dichloride complexes [(C^N)AuCl2]. X‐ray crystallographic analysis revealed that the bidentate BINOL ligands tautomerized and bonded to the AuIII atom through C,O‐chelation to form a five‐membered