## 1 Introduction  
Amines are very important targets in organic chemistry since they are key substrates in organic synthesis, as well as in pharmaceutical and agrochemical research fields. In addition, chiral amines have been extensively used as resolving agents [1; 2; 3; 4], starting materials for the preparation of therapeutic drugs [5] and chiral auxiliaries in asymmetric synthesis [6; 7; 8]. Due to this, synthetic chemists have made great efforts in order to implement efficient procedures for the preparation of chiral amines [9; 10] among which the reduction of iminic substrates plays a capital role. In recent years, the asymmetric transfer hydrogenation (ATH) has emerged as a powerful, convenient and wide-spread methodology to perform the reduction of C=X bonds (X = O or NR) [11] and it has become the second most used reduction methodology for this kind of functional group, just behind hydrogations with molecular hydrogen. The ATH protocol presents several advantages: it is operationally simple, proceeds under mild reaction conditions, generally uses low catalyst loadings and avoids the handling of hazardous chemicals such as metallic hydrides or hydrogen gas. The ATH of prochiral ketones affords enantiomerically enriched secondary alcohols with excellent results [12, 13, 14, 15, 16, 17, 18, 19]. Nevertheless, the asymmetric reduction of iminic compounds by transfer hydrogenation yielding chiral amines still remains underdeveloped and represents a challenging objective [20, 21].  
Due to the low electrophilic character of the iminic carbon, substrates in which the nitrogen atom is bonded to an activating group (aryl, alkoxy, amino, sulfinyl, sulfonyl or phosphinyl) are generally used in reduction methodologies leading to chiral amines. The phosphinyl group is very attractive since its removal from the reduction products can be conveniently achieved under mild acidic conditions, leading to the free primary amines [22, 23]. \(N\)-phosphinyl mines have found a variety of synthetic applications in asymmetric processes [10, 24, 25]. For instance, the preparation of chiral amines can be achieved by stereoselective reduction of \(N\)-phosphinyl ketimes through different synthetic approaches such as hydrogenation [26, 27, 28], hydrosiylation [29, 30, 31, 32, 33], Meerwein-Schmidt-Ponndorf-Verley (MSPV) reaction [34] or the use of boron [35] and aluminium hydrides [36].  
Although the transfer hydrogenation protocol has been already applied to the reduction of different iminic substrates bearing alkyl [18], benzyl [17, 18], aryl [17, 18], sulfonyl [13, 18, 37] or sulfinyl [38, 39, 40, 41] groups attached to the nitrogen atom, there are only a few examples on the use of \(N\)-phosphinyl mines as substrates [18, 42]. In the last years, we have been interested in the use of \(\beta\)-amino alcohols as ligands for ruthenium complexes used as catalysts for the ATH of mines, especially \(N\)-(_tert_-butylsulfonyl)imines [38, 40, 41]. Since, to the best of our knowledge, the use of \(\beta\)-amino alcohols as chiral ligands has not been reported so far for the ATH of \(N\)-(diphenylphosphinyl)imines, we became interested in trying to apply our methodology to those substrates. Thereby, herein we present our preliminary results on the reduction of phosphinyl mines in isopropyl alcohol with ruthenium complexes bearing chiral \(\beta\)-amino alcohols.