Thermally Stable Homogeneous Catalysts for Alkane Dehydrogenation

Catalytic alkane dehydrogenations

“…In 2001, Hall and co-workers [66] investigated iridium complexes 20a and 20b containing an anthraphos backbone in the ligands for alkane dehydrogenation (Eq. (16)).…”

Synthesis, characterization, and cyclometalation studies of benzo[1,2-h: 5,4-h′]diquinolines with palladium and platinum

“…One ligand set that has received a lot of attention is the monoanionic tridentate pincer ligands [1], due to their thermal stability [2] and reactivity of their complexes. The trans directing donor atoms (P, N, S, or O), precoordinates to the metal and brings it into proximity of the XeH (X ¼ C, N, Si) backbone, allowing the metal to undergo electrophilic substitution or oxidative addition to form a strong MeC s bond and rigid framework [1c].…”

“…The PCP, NCN, PCN, SCS, as well as the OCO ligands are known (Scheme 1). These complexes have been shown to act as sensors [1c], dehydrogenation/hydrogenation catalysts [1,2], and Heck catalysts [1]. Pd(NCN) complexes with aryl backbones such as 1,3-bis(2-pyridyl) benzene have been challenging to synthesize.…”

Synthesis of a new class of unsymmetrical PCP′ pincer ligands and their palladium (II) complexes: X-ray structure determination of PdCl{C6H3-2-CH2PPh2-6-CH2PBut2}

“…Complexes of these tridenate pincer ligands are sufficiently robust to withstand the elevated temperatures at which the activation of aliphatic C-H and C-Cl bonds become thermodynamically favorable. Thus, these complexes have been found to have remarkable catalytic activity in aliphatic dehydrogenation [2][3][4] and C-C coupling reactions [5][6][7][8].…”

“…Modifications of the benzylic positions and phosphino R groups have been used to ''tune'', the steric, electronic, and stereochemical properties of these ligands thus their metal complexes [9]. PCP pincer ligands with anthryl backbones, as seen in Scheme 1b, and their metal complexes were recently prepared in an effort to generate pincer complexes of even greater thermal stability [3]. In order to elucidate structure-activity relationships, we have synthesized the first examples PCP pincer ligands of the following types: symmetrical bis-phosphinito (Scheme 2a) [6,7]; unsymmetrical bis-phosphinito (Scheme 2b) [10]; and hybrid phosphinito-phosphino (Scheme 2c and d) [11].…”