Water-Soluble Palladium Complex of N′-(pyridin-2-yl)propane-1,3-diamine modified β-Cyclodextrin: An efficient Catalyst for Transfer Hydrogenation of Carbonyl Compounds

Abstract

Synthesis of a water-soluble Pd(II) complex of N′-(pyridin-2-yl)propane-1,3-diamine modified β-cyclodextrin (Pd(II)@PyPDA:β-CD) is reported. The synthesized Pd(II)@ PyPDA:β-CD, characterized by FT−IR, NMR, mass, UV−vis spectroscopies and molecular modeling studies, is used as a homogeneous, ecofriendly and reusable catalyst under mild reaction conditions for transfer hydrogenation of aromatic ketones to secondary alcohols using isopropyl alcohol as a green reducing agent. This homogeneous catalyst is reused five times with only a small decrease in its catalytic activity. The presence of a chiral cavity in cyclodextrin, is found to facilitate significant chiral induction, evident from preliminary chiral HPLC studies. A plausible mechanism for hydrogenation is proposed. Other significant advantages of the present catalyst, namely, simple preparation, stability, substrate selectivity, easy recovery, and reusability highlight its potential utility in other reactions and also in industrial applications.

A green protocol for the one-pot synthesis of 3,4-disubstituted isoxazole-5(4H)-ones using modified β-cyclodextrin as a catalyst

“…IR: ν (cm −1 ), 3367 (OH), 1641 (Ph-SO 2− ). www.nature.com/scientificreports/ 41,42 . At this step, 1 g of 6-OTs-β-CD with 0.07 g metformin hydrochloride was dissolved in 4 mL of DMF, and a few drops (0.1 mL) of Et 3 N as a base were added to the above flask.…”

Synthetic Application of Cyclodextrins in Combination with Metal Ions, Complexes, and Metal Particles

“…Pitchumani and Khan have prepared a water-soluble Pd 2 + complex by modifying βCD with N'-(pyridin-2-yl)propane-1,3diamine (Pd 2 + -3-βCD). [31] The synthesis included the reaction of tosylated βCD with propane-1,3-diamine then with 2-bromopyridine and, finally, loading of Pd(OAc) 2 . Complex formation was evidenced by considerable downfield shifts of the alkyl and 2pyridyl protons.…”

Biomass-derived Fe-NC hybrid for hydrogenation with formic acid: control of Fe-based nanoparticle distribution

“…Catalytic hydrogenation undoubtedly has the advantages of high atom utilization but also inevitably brings dangers of high temperature and pressure as well. 7,8 Fortunately, the CTH method, in which the hydrogen supply reagent, such as, NH 3 $BH 3 , 9 HCOOH (FA), 10,11 and isopropyl alcohol, 12 is used as a reductant, could overcome the disadvantages of catalytic hydrogenation in view of the mild reaction conditions, safe and simple process, etc. Compared with other reductants, FA, with great application prospects in hydrogen generation, is nontoxic, renewable and easily available.…”