(Trifluoroacetimidoyl)lithiums and Their Reaction with Electrophiles

Trifluoroacetimidoyl halides: a potent synthetic origin

“…Uneyama and co-workers further investigated the generation and chemical properties of the trifluoroacetimidoyl lithiums (Scheme 6). 21 The common imidoyl lithiums are stable only below −60°C due to the highly ionic nature of a carbon-lithium bond. As for the benzoylation reaction with benzoyl chloride, the solvent of the reaction was complex and the lower temperature was beneficial for the reaction because the yield sharply dropped with the increase in temperature.…”

Synthesis of 3,3,4,4-tetrafluoro-1,2-bis(imino)cyclobutanes: A cyclic version of fluorinated α-diimines

“…8 H,3.77 (s,6 H,, 0.00 (s, 18 H (CH 3 ) 3 Si). 19 F NMR (188 MHz,CDC1 3 ): d 72.4 (dd,J = 28,9,2 F),67.3 (dd,J = 28,9,2 F). Anal Calcd for C 24 H 32 F 4 N 2 O 2 Si 2 : C, 56.23; H, 6.29;N,5.46.…”

“…Upon treatment with SmI 2 (4 mol eq. to 3n), iodine-samarium exchange takes place to generate imidoyl samarium species 8, which readily isomerizes to aminocarbene species 9 [9]. Dimerization of aminocarbene 9 and the subsequent hydrolysis give enediamine 11, which is oxidized by MnO 2 to afford a-diimine 1n.…”

Product Class 7: Imines

“…[187] The reaction of various imidoyl chlorides 58 with an excess of lithium powder and a catalytic amount of naphthalene (4 mol%) leads to a solution of the corresponding imidoyllithium intermediates, which by treatment with electrophiles such as aldehydes, ketones, and chloroformates affords a wide variety of imines 59 (Scheme 25). [214] Similarly, by halogen-lithium exchange of 2,2,2-trifluoroacetimidoyl iodide with butyllithium, followed by alkylation with acyl chlorides, aldehydes, ketones, and chlorotrimethylsilane, functionalized imines are obtained; [222] yields vary from 20 to 89%. In the case of the reaction of 2,2,2-trifluoroacetimidoyl chloride with butyllithium, substitution of chloride by the butyl group occurs.…”