A Versatile Route to (E)- and (Z)-2-Hydroxy-3,4-unsaturated Disubstituted Sulfilimines and Their Haloamidation Reaction

Abstract

Alpha-chloro ynones have been reduced using Noyori's Ru catalyst to furnish alpha-chloro propargylic alcohols with excellent enantioselectivity. These have been used as a common precursor for the preparation of (E)- and (Z)-2-hydroxy-3,4-unsaturated disubstituted sulfilimines. The latter serve as precursors for the highly regio- and stereoselective preparation of bromo carbamates.

Are Alkyne Reductions Chemo-, Regio-, and Stereoselective Enough To Provide Pure (Z)-Olefins in Polyfunctionalized Bioactive Molecules?

“…453 A tosyl group did not show such a problem. 454 Since Brown's publication in 1973 showing the potential in the semihydrogenation of alkynes, natural product chemists emphasized the effectiveness of P2−Ni catalyst for the hydrogenation of some very complex molecules. Nowadays it is widely used for achieving 120 high stereo-, chemo-, and regioselectivity.…”

Electron-Deficient Alkynes as Powerful Tools against Root-Knot Nematode Melodogyne incognita: Nematicidal Activity and Investigation on the Mode of Action

“…Reaction progress was monitored by thin-layer chromatography (TLC) using Aldrich silica gel 60 F254 (0.25 mm) plates. 1 H and 13 C nuclear magnetic resonance (NMR) spectra were recorded on a Varian Unity Inova 500 MHz spectrometer. High-resolution mass spectrometry (HRMS) spectra were recorded using an Agilent 6520 liquid chromatography quadrupole time-of-flight mass spectrometry (LC−QTOF−MS) system.…”

“…The acetylene derivatives 1 , 2 , 4 – 8 , and 10 – 17 shown in Figure were purchased from Sigma-Aldrich, Merck Group (Milan, Italy), Alfa Aesar, and Thermo Fisher Scientific. According to the literature, compounds 3 , 9 , 20 , and 21 were prepared as follows.…”

“…and 13 Hz, 1H, HCHSH), 2.05 (s, 3H, CHCHCOCH 3 ), 1.97 (s, 3H, CH 3 CO) 13. C NMR (500 MHz, DMSO): δ 197.05, 173.18, 171.45, 146.23, 142.30, 131.34, 130.09, 128.85, 127.64, 54.15, 46.35, 27.84, 25.72.…”

DFT mechanistic investigation of the 1,2‐reduction of α,β‐unsaturated ynones

“…The importance of the resulting α,β-unsaturated alcohols (3) is irrefutable, as they serve as essential intermediates in organic syntheses [1][2][3][4][5][6][7][8] and might possess biological activity. [9][10][11][12][13][14][15][16][17] These reactions utilize mostly transition metals as catalysts [18][19][20][21][22][23][24] and often require unfavorable conditions. [22][23][24][25][26][27] Although, there is evidence of chemoselective reductions at room temperature with easily attainable reagents.…”