1246224-44-1Relevant articles and documents
Et2Zn-promoted β-trans-selective hydroboration of ynamide
Wang, Kefeng,Zhuang, Zixi,Ti, Huihui,Wu, Peishan,Zhao, Xin,Wang, Honggen
, p. 1564 - 1567 (2020)
The trans-hydroboration of alkyne represents a challenging task in organic synthesis. Reported herein is an Et2Zn promoted β-trans hydroboration of ynamides by using N-heterocyclic carbene (NHC)-ligated borane as boryl source. The reaction leads to a stereoselective construction of enamides bearing a valuable boryl substituent. Both aromatic and aliphatic ynamides were applicable to the reaction. Synthetic transformation of the C–B bond in the product via Suzuki-Miyaura coupling provides a simple and stereospecific route to multi-substituted enamides. Mechanistic studies were conducted and the possible mechanism was discussed
Catalytic Synthesis of Dibenzazepines and Dibenzazocines by 7-Exo- and 8-Endo-Dig-Selective Cycloisomerization
Ito, Mamoru,Takaki, Asahi,Okamura, Moeka,Kanyiva, Kyalo Stephen,Shibata, Takanori
supporting information, p. 1688 - 1692 (2021/03/22)
The 7-exo- and 8-endo-dig-selective gold-catalyzed cycloisomerizations of 2-propargylamino biphenyl derivatives were developed. The reaction of terminal alkynes gave dibenzo[b,d]azepines by 7-exo-dig cycloisomerization. In contrast, when internal alkynes were subjected to the reaction, 8-endo-dig cycloisomerization proceeded to provide dibenzo[b,d]azocines. The nucleophilicity at the reaction site and the electron-withdrawing effect of a tosyl group were important for the present selective transformation. This protocol could be used for ynamide substrates and a silver-catalyzed reaction gave 7-exo-dig products selectively.
Sulfilimines as Versatile Nitrene Transfer Reagents: Facile Access to Diverse Aza-Heterocycles
Tian, Xianhai,Song, Lina,Rudolph, Matthias,Rominger, Frank,Oeser, Thomas,Hashmi, A. Stephen K.
supporting information, p. 3589 - 3593 (2019/02/09)
We herein report the unprecedented synthesis of diverse biologically important aza-heterocycles by employing sulfilimines as nitrene transfer reagents. This class of sulfur-based aza-ylides had not been successfully used for gold nitrene transfer before. This work contains an efficient generation of α-imino gold carbenes by N?S cleavage of sulfilimines. These gold carbenes undergo C?H insertion, cyclopropanation, and nucleophilic attack to form indoles (44 examples), 3-azabicyclo[3.1.0]hexan-2-imines (24 examples), and imidazoles (3 examples). Our study represents a unique gold-catalyzed reaction between alkynes and sulfur ylides, and also includes the first aza-heterocycle synthesis that proceeds by intermolecular nitrene transfer followed by cyclopropanation of the α-imino gold carbenes. Moreover, an unexpected synthesis of 4-acylquinolines (3 examples) from 2-acylphenyl sulfilimines and propargylic silyl ether derivatives by a 1,2-hydride shift onto the α-imino gold carbene and a subsequent Mukaiyama aldol cyclization was discovered.
