Sulfilimines as Versatile Nitrene Transfer Reagents: Facile Access to Diverse Aza-Heterocycles
作者:Xianhai Tian、Lina Song、Matthias Rudolph、Frank Rominger、Thomas Oeser、A. Stephen K. Hashmi
DOI:10.1002/anie.201812002
日期:2019.3.11
We herein report the unprecedented synthesis of diverse biologically important aza‐heterocycles by employing sulfilimines as nitrenetransfer reagents. This class of sulfur‐based aza‐ylides had not been successfully used for gold nitrenetransfer 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
<i>N</i>-Pyridinyl Sulfilimines as a Source for α-Imino Gold Carbenes: Access to 2-Amino-Substituted <i>N</i>-Fused Imidazoles
作者:Xianhai Tian、Lina Song、Matthias Rudolph、Qian Wang、Xinlong Song、Frank Rominger、A. Stephen K. Hashmi
DOI:10.1021/acs.orglett.9b00140
日期:2019.3.15
ynamides is reported. A diverse set of imidazole derivatives is prepared from the corresponding sulfilimines and ynamides. These functionalized cyclic products can undergo further transformations to afford diverse imidazole frameworks. Moreover, in situ synthesis is feasible and shows good potential in the synthesis of nucleoside analogues.
Atmospheric Oxygen Facilitated Oxidative Amidation to α-Ketoamides and Unusual One Carbon Degradative Amidation to <i>N</i>-Alkyl Amides
作者:Jaydeepbhai P. Jadav、Jigarkumar K. Vankar、Ankush Gupta、Guddeangadi N. Gururaja
DOI:10.1021/acs.joc.3c00457
日期:2023.11.17
form oxidative amidation product α-ketoamides and unusual degradative amidation product N-alkyl amides by simply changing the amine substitute. Atmospheric air containing molecular oxygen proved to be an ideal oxidant for an amidation reaction. Under similar conditions, the electron-deficient gem-dibromoalkenes play a dual role with different formamides forming novel oxidative amidation products and
Pd-Catalyzed Domino Synthesis of Internal Alkynes Using Triarylbismuths as Multicoupling Organometallic Nucleophiles
作者:Maddali L. N. Rao、Deepak N. Jadhav、Priyabrata Dasgupta
DOI:10.1021/ol1004164
日期:2010.5.7
The domino coupling reaction of 1,1-dibromo-1-alkenes with triarylbismuth nucleophiles has been demonstrated to furnish disubstituted alkynes directly under catalytic palladium conditions. The couplings of triarylbismuths as multicoupling nucleophiles with 3 equiv of 1,1-dibromo-1alkenes are very fast, affording high yields of alkynes in a short reaction time. Thus, an efficient domino process has been accomplished using 1,1-dibromo-1-alkenes as surrogates for internal alkyne synthesis in couplings with triarylbismuths in a one-pot operation.
Synthesis and Photophysical Studies of Bis-enediynes as Tunable Fluorophores
作者:Gil Tae Hwang、Hyung Su Son、Ja Kang Ku、Byeang Hyean Kim
DOI:10.1021/ja0349148
日期:2003.9.1
We have synthesized a family of bis-enediynes by two complementary Pd/Cu-catalyzed Sonogashira cross-coupling methods. One is a modified Sonogashira reaction between the TMS-protected tetraalkyne 20 (or 21) and various aromatic bromides to afford bis-enediynes 22a-d and 23a-d bearing different peripheral aryl units. The other, the reaction of bifunctional 1,1-dibromo-1-alkenes with phenylacetylene, afforded a series of bis-enediynes 24-32 bearing various core aryl groups. These chemical modifications to the core and periphery of bis-enediynes induce dramatic changes in absorption and emission spectra. Bis-enediynes 22 and 23 show a large Stokes shift of about 50-110 nm when compared to the less-conjugated bis-enediynes 20 and 21. Absorptions and emissions of bis-enediynes 25, 27-29, and 31 were red-shifted relative to those of enediyne 35. Substantial increases in fluorescence quantum yields are observed as a result of extending the T-conjugation. The emission wavelength of bis-enediynes was tailored from indigo blue to reddish-orange, suggesting that the color of emission can be tunable by modification of the core and/or peripheral units.