scholarly journals A Bifunctional Iminophosphorane Squaramide Catalyzed Enantioselective Synthesis of Hydroquinazolines via Intramolecular Aza-Michael Reaction to α,β-Unsaturated Esters

2021 ◽  
Author(s):  
guanglong su ◽  
Connor J Thompson ◽  
Ken Yamazaki ◽  
Daniel Rozsar ◽  
Kirsten Christensen ◽  
...  
Keyword(s):  
Michael Reaction ◽  
Enantioselective Synthesis ◽  
Efficient Synthesis ◽  
Unsaturated Esters ◽  
High Degree

An efficient synthesis of enantioenriched hydroquinazoline cores via a novel bifunctional iminophosphorane squaramide catalyzed intramolecular aza-Michael reaction of urea-linked α,β-unsaturated esters, is described. The methodology exhibits a high degree of...

An Efficient Synthesis of α-Isothiocyanato-α,β-unsaturated Esters from Morita-Baylis-Hillman Adducts

2016 ◽  
Vol 37 (4) ◽  
pp. 592-595 ◽  
Author(s):  
Ko Hoon Kim ◽  
Su Yeon Kim ◽  
Junseong Lee ◽  
Jae Nyoung Kim
Keyword(s):  
Efficient Synthesis ◽  
Unsaturated Esters

Enantioselective synthesis of (R)-tolterodine using lithiation/borylation–protodeboronation methodology

2012 ◽  
Vol 90 (11) ◽  
pp. 965-974 ◽  
Author(s):  
Stefan Roesner ◽  
Varinder K. Aggarwal
Keyword(s):  
Enantioselective Synthesis ◽  
High Yield ◽  
Magnesium Bromide ◽  
Efficient Synthesis ◽  
Boronic Ester ◽  
Better Than

The synthesis of the pharmaceutical (R)-tolterodine is reported using lithiation/borylation–protodeboronation of a homoallyl carbamate as the key step. This step was tested with two permutations: an electron-neutral aryl Li-carbamate reacting with an electron-rich boronic ester and an electron-rich aryl Li-carbamate reacting with an electron-neutral boronic ester. It was found that the latter arrangement was considerably better than the former. Further improvements were achieved using magnesium bromide in methanol leading to a process that gave high yield and high enantioselectivity in the lithiation/borylation reaction. The key step was used in an efficient synthesis of (R)-tolterodine in a total of eight steps in a 30% overall yield and 90% ee.

Enantioselective Synthesis of 3,4-Dihydropyran Derivatives via Organocatalytic Michael Reaction of α,β-Unsaturated Enones

2012 ◽  
Vol 77 (8) ◽  
pp. 4136-4142 ◽  
Author(s):  
Yangbin Liu ◽  
Xiaohua Liu ◽  
Min Wang ◽  
Peng He ◽  
Lili Lin ◽  
...  
Keyword(s):  
Michael Reaction ◽  
Enantioselective Synthesis

ChemInform Abstract: A Highly syn-Selective Michael Reaction of Enamines with α,β-Unsaturated Esters via Cationic Intermediates.

ChemInform ◽  
1990 ◽  
Vol 21 (3) ◽  
Author(s):  
Y. HASHIMOTO ◽  
S. MACHIDA ◽  
K. SAIGO ◽  
J. INOUE ◽  
M. HASEGAWA
Keyword(s):  
Michael Reaction ◽  
Unsaturated Esters

Highly Efficient Synthesis of N 1-Substituted 1H-Indazoles by DBU-Catalyzed Aza-Michael Reaction of Indazole with Enones

Synthesis ◽  
2016 ◽  
Vol 48 (08) ◽  
pp. 1139-1146 ◽  
Author(s):  
Jingya Yang ◽  
Yunfen Bao ◽  
Hongyan Zhou ◽  
Tianyuan Li ◽  
Nana Li ◽  
...  
Keyword(s):  
Michael Reaction ◽  
Efficient Synthesis ◽  
Highly Efficient

A short synthesis of both enantiomers of enterolactone

2000 ◽  
Vol 78 (1) ◽  
pp. 133-138 ◽  
Author(s):  
Mukund P Sibi ◽  
Pingrong Liu ◽  
Michael D Johnson
Keyword(s):  
Key Words ◽  
Enantioselective Synthesis ◽  
Efficient Synthesis ◽  
Short Synthesis

A short and efficient synthesis of both enantiomers of enterolactone, a mammalian lignan, is described. The overall yield for the natural enterolactone, over seven steps, was 19% and for its enantiomer 27%. Key words: enterolactone, 4-diphenylmethyl-2-oxazolidinone, succinate, enantioselective synthesis.

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