Reactions of Bis(trimethylsilyl)ketene Acetals with Several Activated Organic Substrates

Abstract

Bis(trimethylsilyl)ketene acetals have been used in organic synthesis as useful agents for several purposes in conjunction with activated chemical compounds to afford linear, homocyclic, and heterocyclic structures.

Synthesis, Cytotoxic Activity and In Silico Study of Novel Dihydropyridine Carboxylic Acids Derivatives

“…Moreover, many pyridine derivatives such as 1,4-dihydropyridines are of special interest in drug design since they display interesting applications, for example: antibacterial [16], antifungal [17], anti-HIV [18], antihypertensive [19], and anticancer activities, among others, highlighting that any modification within the structure of dihydropyridine can be associated with excellent medicinal effects, decrease tumor growth, cell migration, and principally to avoid resistance of cancer cells against anticancer drugs [20]. As a part of our research interest, some members of our group have appropriately employed bis(trimethylsilyl) ketene acetals in combination with aza-aromatic substrates activated with triflic anhydride as an electrophilic activating agent to produce dihydropyridine carboxylic acids [21].…”

Synthesis of novel isoxazoline and isoxazolidine derivatives: carboxylic acids and delta bicyclic lactones via the nucleophilic addition of bis(trimethylsilyl)ketene acetals to isoxazoles

“…7,[12][13][14][15][16][17][18] Furthermore, these structures are found in a number of natural products. 1,[19][20][21] Over the last two decades, our research group and others have been interested in the nucleophilic addition of bis(trimethylsilyl)ketene acetals to different activated heterocyclic substrates 22 such as pyridine, [23][24][25][26][27][28] pyrazine, [29][30][31] quinoline, 32,33 imidazole, 34 4-azabenzimidazole 35 and 4,5-dihydrooxazole 36 derivatives. In most cases, the main products of these reactions are carboxylic acids which can be transformed into the corresponding γ or δ lactones via the addition of electrophilic species which promote an intramolecular cyclization.…”

Addition of bis(trimethylsilyl)ketene acetals to activated 2-(pyridin-3-yl)-1,3-benzothiazole: Synthesis and cytotoxic activity of novel carboxylic acids and δ-bromolactone derivatives

“…19 Among the synthetic methods to obtain 1,4-DHPs, the addition of nucleophiles to N-activated pyridines stands out from others, as it allows access to derivatives with high regio-and stereoselectivity. 20 In this context, our group have developed new methods based upon the inherent reactivity of bis(trimethylsilyl)ketene acetals to act as 1,3-carbon-oxygen dinucleophiles to allow access to novel carboxylic acid substituted 1,4-DHP and other dihydro(aza-aromatic) compounds using pyridine or other wide-ranging aza-aromatic substrates. 21 These transformations occur by activation of nitrogen atoms via the formation of the corresponding salts with triflic anhydride or by interaction with alkyl chloroformates.…”