Asymmetric Syntheses with Aziridinecarboxylate and Aziridinephosphonate Building Blocks

2006 ◽  
pp. 73-115 ◽  
Author(s):  
Ping Zhou ◽  
Bang-Chi Chen ◽  
Franklin A. Davis
Keyword(s):  
Building Blocks ◽  
Asymmetric Syntheses

Enantiopure Cyclic Nitrones: A Useful Class of Building Blocks for Asymmetric Syntheses

Synthesis ◽  
2007 ◽  
Vol 2007 (04) ◽  
pp. 485-504 ◽  
Author(s):  
Alberto Brandi ◽  
Julia Revuelta ◽  
Stefano Cicchi ◽  
Andrea Goti
Keyword(s):  
Building Blocks ◽  
Asymmetric Syntheses ◽  
Cyclic Nitrones

Applications and stereoselective syntheses of P-chirogenic phosphorus compounds

2016 ◽  
Vol 45 (20) ◽  
pp. 5771-5794 ◽  
Author(s):  
Mathieu Dutartre ◽  
Jérôme Bayardon ◽  
Sylvain Jugé
Keyword(s):  
Building Blocks ◽  
Phosphorus Compound ◽  
Phosphorus Compounds ◽  
Asymmetric Syntheses ◽  
Review Reports ◽  
Stereoselective Syntheses

This review reports the best stereoselective or asymmetric syntheses, the most efficient P*-building blocks and functionalisation of P-chirogenic compounds, in the light of chiral phosphorus compound applications.

Asymmetric Syntheses with Aziridinecarboxylate and Aziridinephosphonate Building Blocks

ChemInform ◽  
2007 ◽  
Vol 38 (51) ◽  
Author(s):  
Ping Zhou ◽  
Bang-Chi Chen ◽  
Franklin A. Davis
Keyword(s):  
Building Blocks ◽  
Asymmetric Syntheses

Asymmetric syntheses of (8R,8aS)- and (8R,8aR)-8-hydroxy-5-indolizidinones: Two promising oxygenated indolizidine building blocks

2011 ◽  
Vol 54 (5) ◽  
pp. 737-744 ◽  
Author(s):  
HongKui Zhang ◽  
Xin Li ◽  
Huang Huang ◽  
PeiQiang Huang
Keyword(s):  
Building Blocks ◽  
Asymmetric Syntheses

Enantiopure Cyclic Nitrones: A Useful Class of Building Blocks for Asymmetric Syntheses

ChemInform ◽  
2007 ◽  
Vol 38 (23) ◽  
Author(s):  
Julia Revuelta ◽  
Stefano Cicchi ◽  
Andrea Goti ◽  
Alberto Brandi
Keyword(s):  
Building Blocks ◽  
Asymmetric Syntheses ◽  
Cyclic Nitrones

scholarly journals Silyldienolates in Organocatalytic Enantioselective Vinylogous Mukaiyama-Type Reactions: A Review

Molecules ◽  
2021 ◽  
Vol 26 (22) ◽  
pp. 6902
Author(s):  
Leon Hoppmann ◽  
Olga García Mancheño
Keyword(s):  
Bond Formation ◽  
Building Blocks ◽  
Transition Metal Catalysis ◽  
Biologically Active ◽  
Formation Processes ◽  
Asymmetric Syntheses ◽  
Metal Catalysis ◽  
Michael Reactions ◽  
Mukaiyama Aldol ◽  
Long Time

Mukaiyama aldol, Mannich, and Michael reactions are arguably amongst the most important C–C bond formation processes and enable access to highly relevant building blocks of various natural products. Their vinylogous extensions display equally high potential in the formation of important key intermediates featuring even higher functionalization possibilities through an additional conjugated C–C double bond. Hence, it is much desired to develop highly selective vinylogous methods in order to enable unconventional, more efficient asymmetric syntheses of biologically active compounds. In this regard, silyl-dienolates were discovered to display high regioselectivities due to their tendency toward γ-additions. The control of the enantio- and diastereoinduction of these processes have been for a long time dominated by transition metal catalysis, but it received serious competition by the application of organocatalytic approaches since the beginning of this century. In this review, the organocatalytic applications of silyl-dienolates in asymmetric vinylogous C–C bond formations are summarized, focusing on their scope, characteristics, and limitations.

Efficient asymmetric syntheses of alkaloids and medicinally relevant molecules based on heterocyclic chiral building blocks

2014 ◽  
Vol 86 (7) ◽  
pp. 1227-1235 ◽  
Author(s):  
Ai-E Wang ◽  
Pei-Qiang Huang
Keyword(s):  
Asymmetric Synthesis ◽  
Recent Progress ◽  
Building Blocks ◽  
Prostaglandin E ◽  
Asymmetric Syntheses ◽  
Total Syntheses ◽  
Lead Compounds ◽  
Chiral Building Block ◽  
Block Based ◽  
Synthetic Methodologies

AbstractIn this report, we present recent progress in synthetic methodologies based on three heterocyclic chiral building blocks developed from our laboratories. The potential of these chiral building block-based methods in the concise asymmetric synthesis of alkaloids and medicinally interesting molecules has been demonstrated by the total syntheses of 8-aza-prostaglandin E1, 11-hydroxylated analogues of the lead compounds CP-734432 and PF-04475270, (+)-castanospermine, (+)-1-epi-castanospermine, 7-deoxy-6-epi-castanospermine as well as 9-epi-sessilifoliamide J.

Photochemical Evolution of Interstellar/Precometary Organic Material

1997 ◽  
Vol 161 ◽  
pp. 23-47 ◽  
Author(s):  
Louis J. Allamandola ◽  
Max P. Bernstein ◽  
Scott A. Sandford
Keyword(s):  
Origin Of Life ◽  
Building Blocks ◽  
Complex Species ◽  
Infrared Observations ◽  
Interstellar Ice ◽  
Polycyclic Aromatic ◽  
Ultraviolet Photolysis ◽  
The Origin Of Life ◽  
Simple Molecules ◽  
Complex Organic

AbstractInfrared observations, combined with realistic laboratory simulations, have revolutionized our understanding of interstellar ice and dust, the building blocks of comets. Since comets are thought to be a major source of the volatiles on the primative earth, their organic inventory is of central importance to questions concerning the origin of life. Ices in molecular clouds contain the very simple molecules H2O, CH3OH, CO, CO2, CH4, H2, and probably some NH3and H2CO, as well as more complex species including nitriles, ketones, and esters. The evidence for these, as well as carbonrich materials such as polycyclic aromatic hydrocarbons (PAHs), microdiamonds, and amorphous carbon is briefly reviewed. This is followed by a detailed summary of interstellar/precometary ice photochemical evolution based on laboratory studies of realistic polar ice analogs. Ultraviolet photolysis of these ices produces H2, H2CO, CO2, CO, CH4, HCO, and the moderately complex organic molecules: CH3CH2OH (ethanol), HC(= O)NH2(formamide), CH3C(= O)NH2(acetamide), R-CN (nitriles), and hexamethylenetetramine (HMT, C6H12N4), as well as more complex species including polyoxymethylene and related species (POMs), amides, and ketones. The ready formation of these organic species from simple starting mixtures, the ice chemistry that ensues when these ices are mildly warmed, plus the observation that the more complex refractory photoproducts show lipid-like behavior and readily self organize into droplets upon exposure to liquid water suggest that comets may have played an important role in the origin of life.

Laboratory and in-situ analysis of comet dust

1988 ◽  
Vol 46 ◽  
pp. 8-9
Author(s):  
D.E. Brownlee ◽  
A.L. Albee
Keyword(s):  
Electron Microscopy ◽  
Solar System ◽  
Laboratory Study ◽  
Isotopic Analysis ◽  
Building Blocks ◽  
Sem Analysis ◽  
Early Solar System ◽  
Cometary Material ◽  
Comet Dust

Comets are primitive, kilometer-sized bodies that formed in the outer regions of the solar system. Composed of ice and dust, comets are generally believed to be relic building blocks of the outer solar system that have been preserved at cryogenic temperatures since the formation of the Sun and planets. The analysis of cometary material is particularly important because the properties of cometary material provide direct information on the processes and environments that formed and influenced solid matter both in the early solar system and in the interstellar environments that preceded it.The first direct analyses of proven comet dust were made during the Soviet and European spacecraft encounters with Comet Halley in 1986. These missions carried time-of-flight mass spectrometers that measured mass spectra of individual micron and smaller particles. The Halley measurements were semi-quantitative but they showed that comet dust is a complex fine-grained mixture of silicates and organic material. A full understanding of comet dust will require detailed morphological, mineralogical, elemental and isotopic analysis at the finest possible scale. Electron microscopy and related microbeam techniques will play key roles in the analysis. The present and future of electron microscopy of comet samples involves laboratory study of micrometeorites collected in the stratosphere, in-situ SEM analysis of particles collected at a comet and laboratory study of samples collected from a comet and returned to the Earth for detailed study.

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