scholarly journals Concise Enantioselective Synthesis of Oxygenated Steroids via Sequential Copper(II)-Catalyzed Michael Addition/Intramolecular Aldol Cyclization Reactions

2015 ◽  
Vol 137 (45) ◽  
pp. 14341-14348 ◽  
Author(s):  
Nathan R. Cichowicz ◽  
Will Kaplan ◽  
Yaroslav Khomutnyk ◽  
Bijay Bhattarai ◽  
Zhankui Sun ◽  
...  
Keyword(s):  
Michael Addition ◽  
Enantioselective Synthesis ◽  
Cyclization Reactions ◽  
Aldol Cyclization

Intramolecular Michael Addition of N- and O-Centred Nucleophiles to Tethered Acrylates. The Role of Double-Bond Geometry in Controlling the Diastereo- selectivity of Cyclizations Leading to 2,6-Disubstituted Tetrahydropyrans and Piperidines.

1998 ◽  
Vol 51 (1) ◽  
pp. 9 ◽  
Author(s):  
Martin G. Banwell ◽  
Brett D. Bissett ◽  
Chinh T. Bui ◽  
Ha T. T. Pham ◽  
Gregory W. Simpson
Keyword(s):  
Double Bond ◽  
Total Synthesis ◽  
Michael Addition ◽  
Reductive Amination ◽  
Major Product ◽  
Enantioselective Synthesis ◽  
Cyclization Reactions ◽  
Glandular Secretion

The oxyanion derived from hydroxyacrylate E-(5) undergoes smooth intramolecular Michael addition to give the trans-2,6-disubstituted tetrahydropyran (7) as the major product of reaction. In contrast, the oxyanion obtained from isomer Z-(5) cyclizes to give the cis-2,6-disubstituted tetrahydropyran (6) as the major product. Such chemistry has been extended to the enantioselective synthesis of (+)-(6) the acquisition of which constitutes a formal total synthesis of acid (+)-(2), a constituent of the glandular secretion from the civet cat (Viverra civetta). Reductive amination of keto acrylate (12) affords an intermediate amine which cyclizes, in situ, to give the cis-2,6-disubstituted piperidine (26). Analogous treatment of compound (13) delivers the isomeric trans-2,6-disubstituted piperidine (27) as the exclusive product of reaction. Transition state structures have been proposed to account for the diastereoselectivities observed in all of the cyclization reactions.

ChemInform Abstract: Highly Enantioselective Synthesis of α-Fluoro-α-nitro Esters via Organocatalyzed Asymmetric Michael Addition.

ChemInform ◽  
2011 ◽  
Vol 42 (16) ◽  
pp. no-no
Author(s):  
Hai-Feng Cui ◽  
Peng Li ◽  
Xiao-Wei Wang ◽  
Zhuo Chai ◽  
Ying-Quan Yang ◽  
...  
Keyword(s):  
Michael Addition ◽  
Enantioselective Synthesis ◽  
Asymmetric Michael Addition ◽  
Nitro Esters

scholarly journals Enantioselective synthesis of seven-membered carbo- and heterocyles by organocatalyzed intramolecular Michael addition

RSC Advances ◽  
2016 ◽  
Vol 6 (36) ◽  
pp. 30166-30169 ◽  
Author(s):  
James O. Guevara-Pulido ◽  
José M. Andrés ◽  
Deisy P. Ávila ◽  
Rafael Pedrosa
Keyword(s):  
Michael Addition ◽  
Enantioselective Synthesis ◽  
High Yields

Enantioenriched seven membered rings have been prepared in high yields and stereoselectivities by intramolecular Michael addition of functionalized enals catalyzed by Jorgensen–Hayashi catalyst.

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