Cross-metathesis reactions as an efficient tool in the synthesis of fluorinated cyclic beta-amino acids.
The synthesis of enantiomerically pure, cyclic, gamma,gamma-difluorinated beta-amino acids with various ring sizes has been carried out with a cross-metathesis (CM) reaction being one of the key steps, followed by a Dieckmann-type condensation to bring about the cyclization. Subsequent catalytic hydrogenation under microwave irradiation with (-)-8-phenylmenthol as a chiral auxiliary led to the successful chemo- and diastereoselective chemical reduction of the resulting cyclic beta-enamino esters. The efficiency and scope of the CM reaction with different types of fluorinated imidoyl chlorides and unsaturated esters has also been studied in order to determine the optimal reaction conditions with regard to selectivity and reactivity.
Departamento de Química Organica, Universidad de Valencia, E-46100 Burjassot, Spain. santos.fustero@uv.es
Santos
S
Fustero
María
M
Sánchez-Roselló
José Luis
JL
Aceña
Begoña
B
Fernández
Amparo
A
Asensio
Juan F
JF
Sanz-Cervera
Carlos
C
del Pozo
D000598:Amino Acids, Cyclic / Q000138:chemical synthesis* / Q000737:chemistry; D054879:Halogenation; D013237:Stereoisomerism
D000598:Amino Acids, Cyclic