Rhodium(III) biphasic and phase-transfer-catalyzed hydrogenolysis of chloroarenes under exceptionally mild conditions

1991 ◽  
Vol 10 (5) ◽  
pp. 1620-1622 ◽  
Author(s):  
Vladimir V. Grushin ◽  
Howard. Alper
Keyword(s):  
Phase Transfer ◽  
Mild Conditions

Solid-liquid phase-transfer catalysis reactions without solvent; very mild conditions for .beta.-eliminations

1984 ◽  
Vol 49 (6) ◽  
pp. 1138-1140 ◽  
Author(s):  
Jean Barry ◽  
Georges Bram ◽  
Guy Decodts ◽  
Andre Loupy ◽  
Philippe Pigeon ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Phase Transfer Catalysis ◽  
Phase Transfer ◽  
Mild Conditions ◽  
Solid Liquid

Gram-scale Preparation of Acyl Fluorides and Their Reactions with Hindered Nucleophiles

Synthesis ◽  
2021 ◽  
Author(s):  
Michał Tryniszewski ◽  
Michal Barbasiewicz
Keyword(s):  
Phase Transfer ◽  
Lithium Amide ◽  
Acyl Chlorides ◽  
Mild Conditions ◽  
Convenient Procedure ◽  
Halogen Exchange ◽  
Scale Preparation ◽  
Biphasic Mixture ◽  
Sterically Hindered

A series of acyl fluorides was synthesized at 100 mmol scale using phase transfer catalyzed halogen exchange between acyl chlorides and aqueous bifluoride solution. The convenient procedure consists of vigorous stirring of the biphasic mixture at rt, followed by extraction and distillation. Isolated acyl fluorides (usually 7 g to 20 g) display excellent purity, and can be transformed into sterically hindered amides and esters, when treated with lithium amide bases and alkoxides under mild conditions.

Novel coincidence effects in a bimetallic phase transfer catalyzed reaction. Biphasic reduction reactions catalyzed by rhodium carbonylmetallate clusters

1985 ◽  
Vol 63 (6) ◽  
pp. 1157-1160 ◽  
Author(s):  
Ferenc Joó ◽  
Howard Alper
Keyword(s):  
Ammonium Salt ◽  
Quaternary Ammonium ◽  
Quaternary Ammonium Salt ◽  
Phase Transfer ◽  
Nitro Compounds ◽  
Organic Substrate ◽  
Carbonyl Complexes ◽  
Cobalt Carbonyl ◽  
Reduction Reactions ◽  
Mild Conditions

Bimetallic and cluster rhodium carbonyl complexes catalyze the biphasic reduction of nitro compounds under mild conditions (using CO/5 M NaOH, C6H6 or PhCH3). Rate studies indicate the sensitivity of the reaction to the nature of the organic substrate, base concentration, and the temperature. A previously observed bimetallic (Co2(CO)8 and (1,5-HDRhCl)2) and phase transfer catalyzed [R4N+X−] reduction of nitro compounds was found to be a consequence of the inhibition and reactivation of the true catalyst by the quaternary ammonium salt and cobalt carbonyl, respectively.

Highly selective difluoromethylations of β-keto amides with TMSCF2Br under mild conditions

Synlett ◽  
2021 ◽  
Author(s):  
yakun wang ◽  
Shuaifei Wang ◽  
Conghui Zhang ◽  
Ting Zhao ◽  
Yanqin Hu ◽  
...  
Keyword(s):  
Transition Metal ◽  
Amino Alcohol ◽  
Phase Transfer Catalysis ◽  
Phase Transfer ◽  
Mild Conditions ◽  
Convenient Access

Without employing any transition metal and other additives, efficient methods for selective difluoromethylations of β-keto amides with TMSCF2Br reagent have been developed under mild conditions. This protocol allows a convenient access to various α-difluoromethyl β-keto amides with excellent yields (up to 93%) and high C/O regioselectivities (up to 99:1). The C/O selectivity of β-keto amides could be easily reversed and controlled by simply changing the base. This protocol can be easily scaled up and the C-difluoromethylation product could be reduced into CF2H contained amino-alcohol derivatives. Moreover, the first enantioselective electrophilic difluoromethylation of β-keto amides has been achieved by phase-transfer catalysis.

scholarly journals Highly selective difluoromethylations of β-keto amides with TMSCF2Br under mild conditions

2021 ◽  
Author(s):  
Yakun Wang ◽  
Shuaifei Wang ◽  
Conghui Zhang ◽  
Ting Zhao ◽  
Yanqin Hu ◽  
...  
Keyword(s):  
Transition Metal ◽  
Amino Alcohol ◽  
Phase Transfer Catalysis ◽  
Phase Transfer ◽  
Mild Conditions ◽  
Convenient Access

Without employing any transition metal and other additives, efficient methods for selective difluoromethylations of β-keto amides with TMSCF2Br reagent have been developed under alkaline and open-air conditions. This protocol allows a convenient access to various α-difluoromethyl β-keto amides with excellent yields (up to 93%) and high C/O regioselectivities (up to 99:1). The C/O selectivity of β-keto amides could be easily reversed and controlled by simply changing the base. This protocol can be easily scaled up and the C-difluoromethylation product could be reduced into amino-alcohol derivatives. Moreover, the first enantioselective electrophilic difluoromethylation of β-keto amides has been achieved by phase-transfer catalysis.

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