On steroids. XXXVI. Catalytic hydrogenation of steroidal enol acetates; A new synthesis of testosterone and oestradiol

1960 ◽  
Vol 25 (4) ◽  
pp. 1078-1085 ◽  
Author(s):  
J. Fajkoš
Keyword(s):  
Catalytic Hydrogenation ◽  
New Synthesis ◽  
Enol Acetates

Studies of Steroid Ring D Epoxides of Enol Acetates; A New Synthesis of Estriol and of Androstane-3β,16α,17β-triol1

1954 ◽  
Vol 76 (11) ◽  
pp. 2943-2948 ◽  
Author(s):  
Norma S. Leeds ◽  
David K. Fukushima ◽  
T. F. Gallagher
Keyword(s):  
New Synthesis ◽  
Enol Acetates

A chiral approach to 2-deoxystreptamine

1987 ◽  
Vol 65 (7) ◽  
pp. 1443-1451 ◽  
Author(s):  
Hans H. Baer ◽  
Isamu Arai ◽  
Bruno Radatus ◽  
June Rodwell ◽  
Nguyen Chinh
Keyword(s):  
Catalytic Hydrogenation ◽  
Periodate Oxidation ◽  
Optically Active ◽  
Potential Utility ◽  
Isopropylidene Derivative ◽  
Chiral Intermediates ◽  
New Synthesis ◽  
Compound 21 ◽  
Derivatives Of

A new synthesis of 2-deoxystreptamine (21), a component of numerous antibiotics, was developed. Starting from D-mannose, it proceeds through chiral intermediates and is designed to furnish starting points for the preparation of stereospecifically modified derivatives of the meso compound 21. 1,2-Dideoxy-1-nitro-D-manno-heptitol (2), obtainable from mannose by the nitromethane method, was protected as the 4,5:6,7-di-O-isopropylidene derivative 4, which was mesylated or triflated in position 3. From the sulfonic esters (5 and 6) two different routes involving displacement by azide, partial deacetonation at O-6,7, periodate oxidation, and cyclization of the resulting nitroaldohexose derivatives converged to give 1L-(1,3/2,4,6)-6-azido-1,2-O-isopropylidene-4-nitro-1,2,3-cyclohexanetriol (19) as a key intermediate. Catalytic hydrogenation then afforded optically active 4,5-O-isopropylidene-2-deoxystreptamine (23), isolated as its N,N′-diacetyl derivative 24. Deacetonation of 19 gave the azidonitrotriol 15, which was reduced to 21. The potential utility of the chiral intermediates for stereospecific syntheses of deoxystreptamine-containing aminoglycosides is discussed.

Tandem Carbon-Radical Peroxidation−Addition to Carbonyl Groups Reaction. A New Synthesis of Steroidal β-Peroxy Lactones

1996 ◽  
Vol 61 (26) ◽  
pp. 9635-9635
Author(s):  
Alicia Boto ◽  
Rosendo Hernández ◽  
Ernesto Suárez ◽  
Carmen Betancor ◽  
María S. Rodríguez
Keyword(s):  
Carbonyl Groups ◽  
New Synthesis

1,3-Selenaphospholes: A New Synthesis from 1,2,3-Selenadiazoles and Kinetically Stabilized Phosphaalkynes1

Synlett ◽  
1991 ◽  
Vol 1991 (04) ◽  
pp. 356-358 ◽  
Author(s):  
Bernd Burkhart ◽  
Steffen Krill ◽  
Yoshinori Okano ◽  
Wataru Ando ◽  
Manfred Regitz
Keyword(s):  
New Synthesis

A New Synthesis and Analysis of Silica Nanowire Periodically Wrapped by Nano-spheres

2016 ◽  
Vol 31 (5) ◽  
pp. 523
Author(s):  
MA Hong-Bing ◽  
BAI Hua ◽  
XUE Chen ◽  
TAO Peng-Fei ◽  
XU Qun-Feng ◽  
...  
Keyword(s):  
New Synthesis

Nanometer Scale Spectroscopic Visualization of Catalytic Sites During a Hydrogenation Reaction on a Pd/Au Bimetallic Catalyst

2020 ◽  
Author(s):  
hao yin ◽  
Liqing Zheng ◽  
Wei Fang ◽  
Yin-Hung Lai ◽  
Nikolaus Porenta ◽  
...  
Keyword(s):  
Catalytic Hydrogenation ◽  
Density Functional ◽  
Hydrogen Transfer ◽  
Bimetallic Catalyst ◽  
Local Environment ◽  
Hydrogenation Reaction ◽  
Boundary Density ◽  
Catalytic Sites ◽  
Powerful Analytical Tool ◽  
Tip Enhanced Raman Spectroscopy

<p>Understanding the mechanism of catalytic hydrogenation at the local environment requires chemical and topographic information involving catalytic sites, active hydrogen species and their spatial distribution. Here, tip-enhanced Raman spectroscopy (TERS) was employed to study the catalytic hydrogenation of chloro-nitrobenzenethiol on a well-defined Pd(sub-monolayer)/Au(111) bimetallic catalyst (<i>p</i><sub>H2</sub>=1.5 bar, 298 K), where the surface topography and chemical fingerprint information were simultaneously mapped with nanoscale resolution (≈10 nm). TERS imaging of the surface after catalytic hydrogenation confirms that the reaction occurs beyond the location of Pd sites. The results demonstrate that hydrogen spillover accelerates hydrogenation at the Au sites within 20 nm from the bimetallic Pd/Au boundary. Density functional theory was used to elucidate the thermodynamics of interfacial hydrogen transfer. We demonstrate that TERS as a powerful analytical tool provides a unique approach to spatially investigate the local structure-reactivity relationship in catalysis.</p>

Nanometer Scale Spectroscopic Visualization of Catalytic Sites During a Hydrogenation Reaction on a Pd/Au Bimetallic Catalyst

2020 ◽  
Author(s):  
Hao Yin ◽  
Liqing Zheng ◽  
Wei Fang ◽  
Yin-Hung Lai ◽  
Nikolaus Porenta ◽  
...  
Keyword(s):  
Catalytic Hydrogenation ◽  
Density Functional ◽  
Hydrogen Transfer ◽  
Bimetallic Catalyst ◽  
Local Environment ◽  
Hydrogenation Reaction ◽  
Boundary Density ◽  
Catalytic Sites ◽  
Powerful Analytical Tool ◽  
Tip Enhanced Raman Spectroscopy

<p>Understanding the mechanism of catalytic hydrogenation at the local environment requires chemical and topographic information involving catalytic sites, active hydrogen species and their spatial distribution. Here, tip-enhanced Raman spectroscopy (TERS) was employed to study the catalytic hydrogenation of chloro-nitrobenzenethiol on a well-defined Pd(sub-monolayer)/Au(111) bimetallic catalyst (<i>p</i><sub>H2</sub>=1.5 bar, 298 K), where the surface topography and chemical fingerprint information were simultaneously mapped with nanoscale resolution (≈10 nm). TERS imaging of the surface after catalytic hydrogenation confirms that the reaction occurs beyond the location of Pd sites. The results demonstrate that hydrogen spillover accelerates hydrogenation at the Au sites within 20 nm from the bimetallic Pd/Au boundary. Density functional theory was used to elucidate the thermodynamics of interfacial hydrogen transfer. We demonstrate that TERS as a powerful analytical tool provides a unique approach to spatially investigate the local structure-reactivity relationship in catalysis.</p>

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