3333-16-2Relevant academic research and scientific papers
Lithium naphthalenide-induced reductive alkylation and addition of aryl-and heteroaryl-substituted dialkylacetonitriles
Tsao, Jing-Po,Tsai, Ting-Yueh,Chen, I-Chia,Liu, Hsing-Jang,Zhu, Jia-Liang,Tsao, Sheng-Wei
scheme or table, p. 4242 - 4250 (2011/02/25)
Lithium naphthalenide (LN)-induced reductive alkylation/addition reactions of aryl-, pyridyl-, and 2-thienyl-substituted dialkylacetonitriles have been investigated. Upon treatment with LN in THF at -40°C, both aryl and pyridyl precursors could undergo the reductive decyanation smoothly, and the in situ generated carbanions could be readily trapped by alkyl halides, ketones, aldehydes, or even oxygen to afford a wide range of functionalized aromatic derivatives bearing a newly established quaternary carbon. To effect the desired reductive alkylation of 2-thienyldialkylacetonitriles, a much lower temperature such as -100°C was required. Also with these substrates, an interesting ring-opening/S-alkylation process was observed when the reductive alkylation were performed at -78°C to give 1-alkylsulfanyl-1,3,4-trienes. A mechanistic discussion is given for this observation.
Mono- vs. dialkylation of carbanions. Effects of absolute and relative acidity of the conjugate carbon acids in selectivity control
Ridvan, Ludek,Zavada, Jiri
, p. 14793 - 14806 (2007/10/03)
The title problem was investigated in the reaction of the dibromide 1 with carbanions 2a-2g covering a range greater than 15 pK units in DMSO. It was found that the bis(monoalkylated) product 3 arises exclusively or predominantly from the carbanions 2d-2g derived from the less acidic carbon acids 7d-7g whereas the cyclic product of dialkylation 4 prevails in the reaction of the carbanions 2a-2c derived from the more acidic carbon acids 7a-7c. The alkylation selectivity thus depends critically on the absolute acidity of the carbon acid participating in the reaction. Rationale for this novel, and on basis of earlier studies unexpected finding is provided in terms of eqs. (1)-(4).
Selective mono-benzylation of methylene active compounds with dibenzyl carbonate: benzylation of phenol
Selva, Maurizio,Marques, Carlos Alberto,Tundo, Pietro
, p. 1889 - 1894 (2007/10/02)
Dibenzyl carbonate (DBzlC) has been used to benzylate phenylacetonitrile, benzyl phenylacetate and phenol.In refluxing N,N-dimethylformamide (DMF) as solvent, and in the presence of K2CO3 phenol yielded benzyl phenyl ether and phenylacetonitrile the monobenzylated compound 2,3-diphenylpropionitrile.Likewise, in refluixing N,N-diethylformamide (DEF), benzyl phenyl acetate gave the benzyl 2,3-diphenylpropionate.Selectivity in mono-C-benzyl derivatives was 98-99percent at a conversion up to 90percent.Such unusually high selectivity is explained in terms of a mechanism involving, initially, carboxybenzylation followed by benzylation, rather than direct benzylation
Alkylation and hydrolysis of phenylacetonitriles under microwave irradiation
Barbry,Pasquier,Faven
, p. 3007 - 3013 (2007/10/03)
Alkylation of phenylacetonitriles is performed by solid-liquid phase transfer catalysis in 1-3 minutes under microwave irradiation (one hour with a two-phase system). These nitriles can be quickly hydrolysed in a microwave oven to yield the corresponding amides or acids according to the reaction time.
COPOLYESTERAMIDES CONTAINING POLY(ETHYLENE OXIDE) SOFT SEGMENTS AS NEW AND EFFICIENT PHASE-TRANSFER CATALYSTS
Montanari, Fernando,Penso, Michele,Fortuna, Giorgio della,Re, Alberto
, p. 427 - 432 (2007/10/02)
Copolyesteramides, 1, prepared by melt polycondensation of N,N'-bis(4-methoxycarbonylbenzoyl)hexamethylenediamine, 2, 1,6-hexanediol and poly(ethylene glycol) (PEG 1000), are a new class of polymeric phase-transfer catalysts.Their catalytic activity has been tested in nucleophilic aliphatic substitutions, eliminations, alkylations of activated methylene groups, dichlorocyclopropanation of C=C double bonds, reductions of ketones to alcohols and oxydation of primary alcohols to aldehydes.
