Synthesis of 6,6′- and 6-MeO–PEG–BINOL-Ca soluble polymer bound ligands and their application in asymmetric Michael and epoxidation reactions

Using Soluble Polymer Supports To Facilitate Homogeneous Catalysis

“…67 The catalyst 34 was separated from product by evaporating the toluene, redissolving the residue in CH 2 Cl 2 , and precipitating 34 using diethyl ether. In this way, 34 was successfully recycled three times.…”

Single-step synthesis of a radically polymerizable 1,1′-bi-2-naphthol derivative for asymmetric catalysis

“…The development of soluble polymers bearing covalently attached BINOL seems to be a good alternative to the use of, for example, polystyrene resins as carriers for BINOL since soluble systems combine the advantages of both homogeneous and heterogeneous catalysis . To date, only few soluble materials with high activities have been described …”

“…In other approaches, the attachment of BINOL occurs via polymer analogous reactions and also requires several reaction steps, e.g. halogenation and substitution . This means that, unfortunately, a simple and direct synthesis of polymerizable BINOL derivatives has not yet been described in the literature.…”

Synthesis of Poly(Ethylene Glycol)–Supported (R)-BINOL Derivatives and Their First Application in Enantioselective Mukaiyama Aldol Reactions

“…On the other hand, among the large number of ligands being subjected to asymmetric syntheses, C 2 -symmetric 1,1 0 -binaphthyl-2,2 0 -diol (abbreviated as BINOL) and its derivatives have occupied a prominent position. [3] Recently, a number of immobilized soluble or insoluble BINOL derivatives have been synthesized, and the resulting polymersupported BINOL complexes were applied in asymmetric transformations such as aza Diels-Alder reactions, [4] additions of diethyl zinc to aldehydes, [5] carbonyl-ene reactions, [6] sulfoxidation reactions, [5d, 6,7] Strecker-type reactions, [8] Michael additions, [9] 1,3-dipolar cycloadditions, [5d] epoxidations, [9,10] and other transformations. [11] To the best of our knowledge, at present only a few contributions have been reported that deal with soluble PEG-supported catalysts for asymmetric Mukaiyama aldol reactions.…”