A system composed of nickel(II) chloride, lithium metal, a catalytic polymer-supported arene, and ethanol, has been efficiently applied to the conjugate reduction of various α,β-unsaturated carbonyl compounds under very mild reaction conditions.
F. Alonso, I. Osante, M. Yus, Synlett, 2006, 3017-3020.
The reaction of dianions, derived from the reductive opening of phthalan (n=1) or isochroman (n=2) with lithium and a catalytic amount of 4,4′-di-tert-butylbiphenyl (DTBB) at 0°C, with several epoxides gave 1,6- and 1,7-diols, respectively.
M. Yus, T. Soler, F. Foubelo, Tetrahedron, 2002, 58, 7009-7016.
The reaction of aliphatic and aromatic secondary and tertiary N-tritylamines with lithium powder and a catalytic amount of naphthalene led to reductive detritylation affording the corresponding amines in good yields. The trityl group could selectively be removed in the presence of an allyl or a benzyl group.
C. Behloul, D. Guijarro, M. Yus, Synthesis, 2004, 1274-1280.
The reaction of different protected alcohols, amines and amides with lithium and a catalytic amount of naphthalene in THF at low temperature leads to their deprotection under very mild reaction conditions, the process being in many cases chemoselective.
E. Alonso, D. J. Ramón, M. Yus, Tetrahedron, 1997, 53, 14355-14368.
The reduction of a series of alkyl sulfonates to the corresponding hydrocarbons was efficiently performed using a reducing system composed of CuCl2ˇ2H2O, an excess of lithium sand and a catalytic amount of 4,4′-di-tert-butylbiphenyl (DTBB), in tetrahydrofuran at room temperature. The process was also applied to enol and dienol triflates affording alkenes and dienes, respectively.
G. Radivoy, F. Alonso, Y. Moglie, C. Vitale, M. Yus, Tetrahedron, 2005, 61, 3859-3864.
2-substituted pyrrolidines, including nornicotine, can be prepared from very simple materials, such as carbonyl compounds (mainly aromatic aldehydes) and 3-chloropropylamine. In the case of imines derived from aliphatic ketones and aldehydes, this methodology gives significantly lower yields.
M. Yus, T. Soler, F. Foubelo, J. Org. Chem., 2001, 66, 6207-6208.
2-Lithioimidazole was prepared using lithium metal in the presence of a catalytic amount of isoprene in THF at room temperature. By reacting this organolithium compound with carbonyl electrophiles 2-(hydroxyalkyl)imidazoles and 2-(aminoalkyl)imidazoles were obtained in good yields.
R. Torregrosa, I. M. Pastor, M. Yus, Tetrahedron, 2005, 61, 11148-11155.