112741-18-1Relevant academic research and scientific papers
Water-controlled selective preparation of α-mono or α,α′-dihalo ketones: Via catalytic cascade reaction of unactivated alkynes with 1,3-dihalo-5,5-dimethylhydantoin
Wu, Chao,Xin, Xiu,Fu, Zhi-Min,Xie, Long-Yong,Liu, Kai-Jian,Wang, Zheng,Li, Wenyi,Yuan, Zhi-Hui,He, Wei-Min
, p. 1983 - 1989 (2017/06/09)
The control of a reaction that can produce multiple products from the same starting material is a highly attractive and challenging concept in organic synthesis. An efficient protocol for the selective synthesis of α-mono or α,α′-dihalo ketones via a water-controlled three-component thiourea-catalyzed cascade reaction of unactivated alkynes, 1,3-dihalo-5,5-dimethylhydantoin and water has been developed. α-Monohaloketones were obtained in aqueous acetone at 45 °C; conversely, α,α′-dihalo ketones were formed with pure water as the sole solvent at room temperature.
Bromination of enamines from tertiary amides using the petasis reagent: A convenient one-pot regioselective route to bromomethyl ketones
Kobeissi, Marwan,Cherry, Khalil,Jomaa, Wissam
, p. 2955 - 2965 (2013/09/02)
An original one-pot synthesis of bromomethyl ketones is achived using the Petasis reagent (dimethyltitanocene) as a key for enamine generation. Several amides were used to test the limits of the procedure by changing either the alkyl chain R or the amino portion of the starting materials. The enamines generated in situ were allowed to react with bromine at low temperature followed by hydrolysis to yield bromomethyl ketones in excellent yields (85 to 95%). Mechanistic details and optimum conditions for the reaction are briefly discussed. The present approach offers several advantages such as regioselectivity in enamine formation, good yields, mild reaction conditions, and ease of experimentation.
Ester Homologation Revisited: A Reliable, Higher Yielding and Better Understood Procedure
Kowalski, Conrad J.,Reddy, Rajarathnam E.
, p. 7194 - 7208 (2007/10/02)
Enolate anions 3 and 6, prepared via enolization of α-bromo and dibromo ketones 4 and 5 were converted in high yield to ynolate anions 10 by respective addition of lithium tetramethylpiperidide (to effect deprotonation, 3 --> 7) or butyllithium (to effect metal-halogen exchange, 6 --> 7).Mixtures of such enolates were also obtainable from esters 1 on a large-scale (25 mmol) via in situ formation and addition of lithiodibromomethane (from methylene bromide and lithium tetramethylpiperidide), followed by treatment of the resulting adducts with lithiumhexamethyldisilazide to ensure complete enolization.Addition of sec-butyllithium and n-butyllithium to effect ynolate anion formation, followed by quenching of the reaction mixtures into acidic ethanol, reproducibly afforded homologated esters 8 in 67-90percent yield.Demonstrated for ethyl esters 1 having the carbethoxy moiety attached to primary, secondary, tertiary, aryl, and alkenyl groups, this general procedure provides a convenient, large-scale alternative to the classical Arndt-Eistert sequence.
A New Method for the Introduction of Carbon-Carbon Triple Bond at C-13 in PG Synthesis. A Stereocontrolled Synthesis of ZK 96 480
Takahashi, Atsuo,Shibasaki, Masakatsu
, p. 1227 - 1231 (2007/10/02)
ZK 96 480, a chemically and metabolically stable prostacyclin analogue, has been synthesized from the Corey lactone in a stereocontrolled manner by a route utilizing a newlyeveloped method for introduction of the carbon-carbon triple bond at C-13 (PG numb
