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.
Fustero
Santos
S
Departamento de Química Organica, Universidad de Valencia, E-46100 Burjassot, Spain. santos.fustero@uv.es
Sánchez-Roselló
María
M
Aceña
José Luis
JL
Fernández
Begoña
B
Asensio
Amparo
A
Sanz-Cervera
Juan F
JF
del Pozo
Carlos
C
D000598:Amino Acids, Cyclic / Q000138:chemical synthesis* / Q000737:chemistry; D054879:Halogenation; D013237:Stereoisomerism
D000598:Amino Acids, Cyclic