Critical Role of the Coordination Environment of Palladium Dichloride on the Course of Its Reaction with Secondary Benzylic Alcohols:  Selective Oxidation or Etherification Catalysts

Abstract

In refluxing 1,2-dichloroethane under an argon atmosphere, 1-indanol led to a high yield of 1-indanone in the presence of sodium carbonate and catalytic amounts of (R 4 N) 2 PdCl 4 , while the use of PdCl 2 -(RCN) 2 as catalyst afforded di(1-indanyl) oxide quantitatively. These distinct reactive pathways would be due to the different electronic properties of the catalysts. The etherification reaction is limited to primary and secondary benzylic alcohols.

A new versatile binuclear seven-coordinate complex of molybdenum(II), [(μ-Cl)2{Mo(μ-Cl)(SnCl3)(CO)3}2]2−

“…Although the dehydration of alcohols to ethers has been recently observed in the presence of transition metal catalysts [35][36][37][38][39][40][41][42] the formation of ether in one-pot synthesis from olefin is very scarce [43][44]. The reaction catalyzed by 1 not only proceeds under very mild conditions but is selective as well.…”

The Reims Journey Towards Discovery and Understanding of Pd-Catalyzed Oxidations

“…0.5 H 2 O (92% conversion, 90% yield) instead of the PdCl 2 /Adogen 464 association [31]. Surprisingly, soluble (MeCN) 2 PdCl 2 produced di(1-indanyl) oxide (28) in high yields, even in the absence of the base (Equation 15) [49].…”

“…We used this procedure for the oxidation with high yields of benzyl-protected sugar hemiacetals into lactones (Equation (16)) [57]. (15) We rationalized the formation of 21 and 28 through two competitive pathways catalyzed with L 2 PdCl 2 (L = Cl − or RCN), that is with [PdCl 4 ] 2− and (RCN) 2 PdCl 2 , respectively (Scheme 9) [49]. In contrast to the anionic catalyst (L = Cl -), the neutral catalyst (L = RCN) is electrophilic [50][51][52][53].…”

Recent Developments in the Applications of Palladium Complexes Bearing N-Heterocyclic Carbene Ligands

“…A very attractive alternative for the selective oxidation of alcohols is the use of aryl halides as oxidants. [140][141][142] The aryl halide acts as a hydride acceptor and forms the corresponding dehalogenated compound as the only by-product of the reaction. In this particular sense, Navarro's group has described the use of commercially available palladium and nickel complexes with NHC ligands in the oxidation of secondary alcohols using chlorobenzene as oxidant.…”