Catalytic enantioselective boron conjugate addition to cyclic carbonyl compounds: a new approach to cyclic β-hydroxy carbonyls

2009 ◽  
pp. 6577 ◽  
Author(s):  
Xinhui Feng ◽  
Jaesook Yun
Keyword(s):  
Carbonyl Compounds ◽  
Conjugate Addition ◽  
New Approach

Conjugate addition of dimethylphenylsilyllithium to α,β-unsaturated carbonyl compounds mediated by sub-stoichiometric quantities of dimethylzinc

1997 ◽  
Vol 38 (42) ◽  
pp. 7313-7316 ◽  
Author(s):  
Bonnie L. MacLean ◽  
Kimberlea A. Hennigar ◽  
Kevin W. Kells ◽  
Robert D. Singer
Keyword(s):  
Carbonyl Compounds ◽  
Conjugate Addition

Reactions of phenyldimethylsilyllithium with β-N,N-dimethylaminoenones: A convenient synthesis of β-dimethyl(phenyl)silylacrylic acid and its derivatives

2004 ◽  
Vol 82 (2) ◽  
pp. 325-332 ◽  
Author(s):  
Ian Fleming ◽  
Elena Marangon ◽  
Chiara Roni ◽  
Matthew G Russell ◽  
Sandra Taliansky Chamudis
Keyword(s):  
Key Words ◽  
Methyl Iodide ◽  
Carbonyl Compounds ◽  
Conjugate Addition ◽  
Brief Treatment ◽  
Dimethylamino Group ◽  
Convenient Synthesis ◽  
Work Up

Phenyldimethylsilyllithium reacted with 5,5-dimethyl-3-(N,N-dimethylamino)cyclohex-2-enone (7), 3-(E)-N,N-dimethylaminopropenal (11), and 4-N,N-dimethylaminobut-3-en-2-one (13) to give the corresponding β-silyl-α,β-unsaturated carbonyl compounds 8, 12, and 14, in which the dimethylamino group has been displaced by the phenyldimethylsilyl group. Phenyldimethylsilyllithium reacted with ethyl β-N,N-dimethylaminopropenoate (15) by conjugate addition, but, in contrast to the ketones 7 and 13 and the aldehyde 11, the intermediate enolate 16 was C-protonated in the aqueous work-up to give ethyl 3-N,N-dimethylamino-3-dimethyl(phenyl)silylpropanoate (17). When the enolate 16 was instead given a mysteriously brief treatment with methyl iodide before work-up, the product was ethyl 3-(E)-dimethy(phenyl)silylpropenoate (18). Phenyllithium and methyllithium also added conjugatively to ethyl β-N,N-dimethylaminoacrylate (15) but, in contrast to the silyl case, the intermediate enolate 22 reacted unexceptionally with methyl iodide to give the products 25 and 26 of stereoselective C-methylation. This synthesis of the ester 18 was used to synthesize the Oppolzer sultam derivative 30.Key words: conjugate addition, elimination, substitution, silyllithium, silylenone.

Synthesis of Phenyl-2,2′-bichalcophenes and Their Aza-Analogues by Catalytic Oxidative Deacetylation

Synthesis ◽  
2019 ◽  
Vol 51 (17) ◽  
pp. 3259-3268
Author(s):  
Xia Jiang ◽  
Hui Jin ◽  
Tingshu Wang ◽  
Hyebin Yoo ◽  
Sangho Koo
Keyword(s):  
Ethyl Acetoacetate ◽  
Carbonyl Compounds ◽  
Conjugate Addition ◽  
Synthetic Method ◽  
Dicarbonyl Compounds

Efficient synthetic method for medicinally and opto-electronically important bichalcophenes is reported, which highlights Mn(OAc)3/CoCl2-catalyzed oxidative deacetylation of 1,5-dicarbonyl compounds that were easily prepared by conjugate addition of ethyl acetoacetate to α,β-unsaturated carbonyl compounds containing a chalcophene unit. Paal–Knorr reaction of the resulting 1,4-dicarbonyl compounds produced 4-phenyl-2,2′-bichalcophenes and their aza-analogues.

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