125877-36-3Relevant academic research and scientific papers
Convenient Preparations of Diethyl phosphonates, 2-Azabutadienes, and Isoquinolines from a 1,2-Monoazabisylide Equivalent
Katritzky, Alan R.,Zhang, Guifen,Jiang, Jinlong
, p. 4556 - 4560 (2007/10/02)
Diethyl methyl>phosphonate (4), prepared in situ by treatment of 1-methyl>benzotriazole (betmip 6) with diethyl phosphite anion, is converted by treatment with butyllithium into the corresponding carbanion 5.Carbanion 5, the first example of a 1,2-monoazabisylide equivalent, provides a versatile synthetic method to introduce the C=NC=C structural unit, as illustrated by convenient preparations of 1,4-diaryl-2-azabutadienes, 1,1,4,4-tetraaryl-2-azabutadienes, diethyl phosphonates, and isoquinolines.
Silylamines in Organic Synthesis. Reactivity of N,N-Bis(silyl) Enamines toward Electrophiles. A Route to Substituted 2-Aza-1,3-butadienes and Pyridines
Corriu, Robert J. P.,Moreau, Joel J. E.,Pataud-Sat, Magali
, p. 2878 - 2884 (2007/10/02)
N,N-Bis(silyl) enamines appeared to be weak nucleophilic reagents and exhibited a very low reactivity toward electrophiles.However, in the presence of a nucleophilic catalyst, nucleophilic activation of the silicon-nitrogen bond was observed.Under fluoride ion catalysis (TBAF or CsF), N,N-bis(silyl) enamines reacted with carbonyl compounds to give substituted 2-aza-1,3-butadienes.Good yields were obtained in reactions with aromatic aldehydes or ketones.In the case of aliphatic carbonyl compounds, 2-aza 1,3-dienes were only formed in moderate yields.Interestingly, enamidines were easily obtained in high yields upon reactions of dimethylformamide in the presence of MeONa as catalyst.The reaction of aromatic α,β-unsaturated ketones gave 2-aza 1,3,5-trienes, which were not isolated but underwent an intramolecular cycloaddition reaction with regioselective formation of substituted 2,4-diarylpyridines.
Geminal Acylation-Alkylation at a Carbonyl Carbon via Regiospecifically Generated Metalloenamines
Martin, Stephen F.,Phillips, Gerald W.,Puckette, Thomas A.,Colapret, John A.
, p. 5866 - 5872 (2007/10/02)
A useful procedure for effecting geminal disubstitution at the carbonyl carbon atom of aldehydes and ketones has been developed in which the sequence of reactions results in the replacement of the two carbon-oxygen bonds of the carbonyl function with an acyl group and an alkyl or hydroxyalkyl group.Of particular importance is the facile application of these procedures to the efficient construction of quaternary carbon atoms that bear alkyl appendages containing differentiated functionality.This novel methodology features the initial conversion of carbonyl compounds 1 into the substituted 2-azadienes 10 or 11 by Wittig-Horner reaction.Subsequent reaction of these 2-azadienes produced in situ with n-butyllithium results in the formation of the metalloenamines 12 and 13 (R4 = n-Bu) which undergo reactions with a wide variety of electrophiles to give, after hydrolysis of the intermediate imines, the α-substituted aldehydes 14 or the α-substituted ketones 15 in good of excellent overall yields.New procedures for the annelation of cyclopentenones such as 22 and cyclohexenones 26 at the carbonyl carbon of ketones are described as is an important variant of a directed aldol reaction, 1 --> 28.Although a number of individual manipulations are necessary to effect the geminal disubstitution of a carbonyl functional group, it is generally feasible to execute the entire sequence of reactions in single flask, thereby rendering this methodology very convenient to implement in practice.
