2840-69-9Relevant academic research and scientific papers
Synthesis of Cyclic Anhydrides via Ligand-Enabled C–H Carbonylation of Simple Aliphatic Acids
Herron, Alastair N.,Yu, Jin-Quan,Zhuang, Zhe
supporting information, p. 16382 - 16387 (2021/06/23)
The development of C(sp3)–H functionalizations of free carboxylic acids has provided a wide range of versatile C?C and C?Y (Y=heteroatom) bond-forming reactions. Additionally, C–H functionalizations have lent themselves to the one-step preparation of a number of valuable synthetic motifs that are often difficult to prepare through conventional methods. Herein, we report a β- or γ-C(sp3)–H carbonylation of free carboxylic acids using Mo(CO)6 as a convenient solid CO source and enabled by a bidentate ligand, leading to convenient syntheses of cyclic anhydrides. Among these, the succinic anhydride products are versatile stepping stones for the mono-selective introduction of various functional groups at the β position of the parent acids by decarboxylative functionalizations, thus providing a divergent strategy to synthesize a myriad of carboxylic acids inaccessible by previous β-C–H activation reactions. The enantioselective carbonylation of free cyclopropanecarboxylic acids has also been achieved using a chiral bidentate thioether ligand.
Cycloalkylthiazoles
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, (2008/06/13)
The invention relates to compounds of the formula: STR1 wherein R is hydrogen or lower alkyl, R1, R2, R3 and R4, independently, are hydrogen, lower alkyl, lower alkenyl, cycloalkyl or phenyl unsubstituted or substituted by up to 3 substituents independently selected from lower alkyl, lower alkoxy or halogen, or R1 and R2 taken together with the carbon atom are alkylene of 2 to 5 carbon atoms unsubstituted or substituted by lower alkyl, and n is an integer of from 0 to 3, and, when R1 is different from R2 and/or when R3 is different from R4, enantiomers, diastereomers and racemates thereof and, when R is hydrogen, salts thereof with pharmaceutically acceptable bases. The compounds of formula I and, when R is hydrogen, pharmaceutically exceptable salts thereof are useful as bronchopulmonary agents, for example, in the relief of asthma and allergic reactions.
