Synthesis of Nitrogen-Functionalized Cyclohexanes Using Chemoselective Conjugate Addition of Phenyllithium to Linear ω-Nitro-α,β,ψ,ω-Unsaturated Ester and Subsequent Stereoselective Intramolecular Nitro-Michael Cyclization

2004 ◽  
Vol 52 (9) ◽  
pp. 1109-1113 ◽  
Author(s):  
Tomohisa Yasuhara ◽  
Katsumi Nishimura ◽  
Emi Osafune ◽  
Osamu Muraoka ◽  
Kiyoshi Tomioka
Keyword(s):  
Conjugate Addition ◽  
Unsaturated Ester

Total Synthesis of (±)-α- and β-Lycoranes by Sequential Chemoselective Conjugate Addition−Stereoselective Nitro-Michael Cyclization of an ω-Nitro-α,β,ψ,ω-unsaturated Ester

2003 ◽  
Vol 5 (7) ◽  
pp. 1123-1126 ◽  
Author(s):  
Tomohisa Yasuhara ◽  
Katsumi Nishimura ◽  
Mitsuaki Yamashita ◽  
Naoshi Fukuyama ◽  
Ken-ichi Yamada ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Conjugate Addition ◽  
Unsaturated Ester

Metal-Mediated C–C Ring Construction: The Lei Synthesis of (−)-Huperzine Q

2017 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Organic Chemistry ◽  
Conjugate Addition ◽  
Harvard University ◽  
Unsaturated Ester ◽  
Pd Catalyst ◽  
Enantiomerically Pure ◽  
Shanghai Institute ◽  
Diastereoselective Addition ◽  
University Of Bristol ◽  
The University

Following the Szymoniak protocol, Morwenna S. M. Pearson-Long and Philippe Bertus of the Université du Maine added (Synthesis 2015, 47, 992) the Grignard rea­gent 2 to the nitrile 1 to give the cyclopropyl amine 3. Chen-Guo Feng of the Shanghai Institute of Organic Chemistry prepared (Chem. Commun. 2015, 51, 8773) the cyclobutane 6 by enantioselective conjugate addition of 5 to the unsaturated ester 4. Martin Kotora of Charles University showed (Eur. J. Org. Chem. 2015, 2868) that the zirconacycle from the eneyne 7 reacted with the aldehyde 8 to give, after iodina­tion, the alcohol 9. Xiaoming Feng of Sichuan University used (Angew. Chem. Int. Ed. 2015, 54, 1608) a scandium catalyst to effect the intramolecular Roskamp cyclization of 10 to 11. Celia Dominguez of CHDI observed (Org. Lett. 2015, 17, 1401) that the double alkylation of the ester 12 with the dibromide 13 proceeded with high diaste­reoselectivity, to give 14. Hirokazu Tsukamoto of Tohoku University cyclized (Chem. Commun. 2015, 51, 8027) 15 to 16 in high ee. Daniel J. Weix of the University of Rochester found (J. Am. Chem. Soc. 2015, 137, 3237) that under the influence of an enantiomerically-pure Ti catalyst, the organon­ickel species derived from 18 opened the prochiral epoxide 17 to give 19 in high ee. John F. Bower of the University of Bristol optimized (J. Am. Chem. Soc. 2015, 137, 463) conditions for the highly diastereoselective Rh-mediated cyclocarbonylation of 20 to 21. Margaret A. Brimble of the University of Auckland initiated (J. Org. Chem. 2015, 80, 2231) the construction of the cyclohexenone 24 by the diastereoselective addition of 23 to the unsaturated ester 22. Olivier Baslé and Marc Maduit of ENSC Rennes devised (Chem. Eur. J. 2015, 21, 993) conditions for the preparation of 26 by enantioselective conjugate addition to the cyclohexenone 25. Yoshito Kishi of Harvard University demonstrated (Tetrahedron Lett. 2015, 56, 3220) that the carbenoid generated from the epoxide 27 cyclized to 28 with high dia­stereoselectivity. Wenjun Tang, also of the Shanghai Institute of Organic Chemistry, developed (Angew. Chem. Int. Ed. 2015, 54, 3033) a Pd catalyst for the diastereoselec­tive (because it is enantioselective) cyclization of 29 to 30.

A study of conjugate addition to a γ,δ-dioxolanyl-α,β-unsaturated ester

2001 ◽  
Vol 42 (26) ◽  
pp. 4281-4283 ◽  
Author(s):  
Guoxia Han ◽  
Victor J. Hruby
Keyword(s):  
Conjugate Addition ◽  
Unsaturated Ester

A fluorescent probe for biothiols based on the conjugate addition of thiols to α,β-unsaturated ester

Luminescence ◽  
2010 ◽  
Vol 26 (6) ◽  
pp. 486-493 ◽  
Author(s):  
Jun Du ◽  
Zhe Yang ◽  
Haiping Qi ◽  
Xiao-Feng Yang
Keyword(s):  
Fluorescent Probe ◽  
Conjugate Addition ◽  
Unsaturated Ester

scholarly journals Asymmetric Synthesis of Pyrrolizidines, Indolizidines and Quinolizidines via a Double Reductive Cyclisation Protocol

Synlett ◽  
2017 ◽  
Vol 28 (20) ◽  
pp. 2697-2706 ◽  
Author(s):  
Stephen Davies ◽  
Ai Fletcher ◽  
Paul Roberts ◽  
James Thomson
Keyword(s):  
Asymmetric Synthesis ◽  
Conjugate Addition ◽  
Unsaturated Ester ◽  
Asymmetric Syntheses ◽  
Lithium Amide ◽  
Target Molecule

This account describes an overview of the asymmetric syntheses of pyrrolizidines, indolizidines and quinolizidines via a common double reductive cyclisation protocol. The highly diastereoselective conjugate addition of an enantiopure lithium amide to an α,β-unsaturated ester incorporating a terminal C=C bond installed the nitrogen-bearing stereogenic centre and was followed by enolate functionalisation to introduce the second olefinic functionality. Alternatively, conjugate addition to the corresponding α-alkenyl α,β-unsaturated ester followed by α-protonation of the intermediate enolate may also be used to access the cyclisation precursor. After oxidation of the two terminal olefinic units to give the corresponding dialdehyde, tandem hydrogenolysis/hydrogenation was employed to efficiently construct the azabicyclic core of each target molecule. This double reductive cyclisation strategy was successfully utilised in the syntheses of 13 azabicyclic alkaloids or closely related analogues.1 Introduction2 Asymmetric Syntheses of (–)-Isoretronecanol and (–)-Trachelanthamidine3 Asymmetric Syntheses of (+)-Trachelanthamidine [(+)-Laburnine], (+)-Tashiromine and (+)-epi-Lupinine4 Asymmetric Syntheses of (–)-Hastanecine, (–)-Turneforcidine and (–)-Platynecine5 Asymmetric Syntheses of (–)-Macronecine, (–)-Petasinecine, (–)-1-epi-Macronecine, (+)-1-epi-Petasinecine and (+)-2-epi-Rosmarinecine6 Conclusion

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