“…The hydrogenation of alkenes catalyzed by transition metal complexes is a kind of very important reactions [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] and an atom-economical synthetic methodology which has been used extensively in academic and industrial settings [17]. Alkene complexes of transition metals [18][19][20][21][22][23][24] play an important role in understanding the reaction mechanisms for hydrogenation of alkenes, which has been confirmed experimentally and theoretically to proceed via a wide variety of different pathways [25][26][27][28][29][30].…”