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A regioselective fluoromethylation by ring‐opening of cyclic sulfamidates and sulfates with α‐fluorocarbanions and subsequent reductive desulfonylation is developed. Fluorobis(phenylsulfonyl)methane (FBSM) was explored as fluoromethide equivalent and the reaction was extended to the α‐fluorocarbanion of ethyl 2‐fluoroacetoacetate. This approach allows access to γ‐ and δ‐fluoroamines as well as γ‐ and δ‐fluoroalcohols in high yields. [ABSTRACT FROM AUTHOR]

The regioselective ring‐opening of 1,2‐ and 1,3‐sulfamidates with fluorine anion is reported. Direct construction of monofluoro‐substituted amines and amino acid derivatives using inexpensive and easily available potassium fluoride (KF). The monofluorination process only needs 35 minutes under heating, which will be an attractive route for the synthesis of the PET fluorine‐18 radiotracer. The application of the product can be extended to the construction of fluorinated polypeptides after simple deprotection treatment. [ABSTRACT FROM AUTHOR]

Abstract: A telescoping process involving the consecutive addition of four reagents (trifluorodiazoethane, phosphine, allenyl ester, and acetic acid) into a single reactor was developed for the novel functionalization of allenyl esters. First, new phosphazenes derived from trifluorodiazoethane and phosphines were generated and reacted with allenyl esters to give unexpected α‐iminophosphoranes through the creation of C=P, C=N, and C−H bonds at the α‐, β‐, and γ‐carbon atoms, respectively, of the allenyl esters. The α‐iminophosphoranes did not react with aldehydes in a classic Wittig reaction, but instead β‐enamino esters were obtained. The overall sequence of reactions offered a formal hydrohydrazonation of allenyl esters. The method was extended to other related diazo compounds and applied to the preparation of novel 5‐pyrazolone derivatives. Not only is the telescoping process described herein an effective approach for truncating the multistep synthesis, but also each step has been dissected to understand and support the reaction mechanisms. [ABSTRACT FROM AUTHOR]

A novel copper-catalyzed one-pot cross-coupling of β-ketoacids with in situ generated trifluorodiazoethane has been developed. This reaction provides a direct and efficient method, in which one CC bond and one CO bond were formed in a carbenoid center with concomitant denitrogenation-dehydrogenation-decarboxylation, to afford trifluoromethylated aldol products. In several preliminary experiments, good to high enantioselectivities were also obtained. [ABSTRACT FROM AUTHOR]