Block copolymers of cyclic esters and processes for preparing same
AssigneeRamot at Tel-Aviv University Ltd.
InventorsMoshe Kol, Tomer Rosen
Life of this patent
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Abstract
Novel processes of preparing block polyester copolymers while precisely controlling the stereoconfiguration (e.g., tacticity), chemical composition and/or length of each unit (block) are provided. Block polyester copolymers featuring desirable combinations of two or more blocks featuring different stereoconfiguration (e.g., tacticity), chemical composition and/or length, including triblock, tetrablock and higher block copolymers are also provided. A novel family of organometallic magnesium complexes and uses thereof in preparing polyesters and block polyester copolymers are also provided.
Claims17
A process of ring opening polymerization of a cyclic ester, the process comprising contacting a plurality of monomers of said cyclic ester with a catalyst system comprising an organometallic magnesium complex, said organometallic magnesium complex comprising a Mg—X unit and a divergent {ONNN} ligand in coordination with said Mg—X.
An organometallic complex represented by Formula III:
- wherein:
- the dashed line represents a coordinative bond;
- M is magnesium;
- X is a monoanionic ligand;
- m, n and q are each independently an integer of from 1 to 6, or from 1 to 4, or from 1 to 2;
- Ra and Rb are each independently hydrogen, alkyl, cycloalkyl, aryl, heteroaryl, heteroalicyclic, hydroxyl, alkoxy, thiol, thioalkoxy, aryloxy, and amine, wherein when m is other than 1, Ra and Rb in each (CRaRb) unit can be the same or different, and one or both Ra and Rb in one unit can form a 5 to 7-membered alicyclic, heteroalicyclic, aromatic or heteroaromatic ring with one or both Ra and Rb of an adjacent unit;
- Rc and Rd are each independently hydrogen, alkyl, cycloalkyl, aryl, heteroaryl, heteroalicyclic, hydroxyl, alkoxy, thiol, thioalkoxy, aryloxy, and amine, wherein when n is other than 1, Rc and Rd in each (CRcRd) unit being the same or different, and one or both Rc and Rd in one unit optionally forms a 5 to 7-membered alicyclic, heteroalicyclic, aromatic or heteroaromatic ring with one or both Rc and Rd of an adjacent unit;
- Rz and Rw are each independently hydrogen, alkyl, cycloalkyl, aryl, heteroaryl, heteroalicyclic, hydroxyl, alkoxy, thiol, thioalkoxy, aryloxy, and amine, wherein when q is other than 1, Rz and Rw in each (CRzRw) unit being the same or different, and one or both Rz and Rw in one unit optionally forms a 5 to 7-membered alicyclic, heteroalicyclic, aromatic or heteroaromatic ring with one or both Rz and Rw of an adjacent unit;
- and
- R41-R48 and R3-R56 are each independently selected from the group consisting of hydrogen, alkyl, cycloalkyl, aryl, halo, alkoxy, aryloxy, trialkylsilyl, heteroalicyclic, heteroaryl, and amine,
- provided that:
- X is other than alkoxy or aryloxy;
- and/or
- at least one of R41 and R42 is a bulky rigid alkyl.
A ligand precursor represented by Formula IV:
- wherein:
- m, n and q are each independently an integer of from 1 to 6, or from 1 to 4, or from 1 to 2;
- Ra and Rb are each independently hydrogen, alkyl, cycloalkyl, aryl, heteroaryl, heteroalicyclic, hydroxyl, alkoxy, thiol, thioalkoxy, aryloxy, and amine, wherein when m is other than 1, Ra and Rb in each (CRaRb) unit can be the same or different, and one or both Ra and Rb in one unit can form a 5 to 7-membered alicyclic, heteroalicyclic, aromatic or heteroaromatic ring with one or both Ra and Rb of an adjacent unit;
- Rc and Rd are each independently hydrogen, alkyl, cycloalkyl, aryl, heteroaryl, heteroalicyclic, hydroxyl, alkoxy, thiol, thioalkoxy, aryloxy, and amine, wherein when n is other than 1, Rc and Rd in each (CRcRd) unit being the same or different, and one or both Rc and Rd in one unit optionally forms a 5 to 7-membered alicyclic, heteroalicyclic, aromatic or heteroaromatic ring with one or both Rc and Rd of an adjacent unit;
- Rz and Rw are each independently hydrogen, alkyl, cycloalkyl, aryl, heteroaryl, heteroalicyclic, hydroxyl, alkoxy, thiol, thioalkoxy, aryloxy, and amine, wherein when q is other than 1, Rz and Rw in each (CRzRw) unit being the same or different, and one or both Rz and Rw in one unit optionally forms a 5 to 7-membered alicyclic, heteroalicyclic, aromatic or heteroaromatic ring with one or both Rz and Rw of an adjacent unit;
- and
- R41-R48 and R53-R56 are each independently selected from the group consisting of hydrogen, alkyl, cycloalkyl, aryl, halo, alkoxy, aryloxy, trialkylsilyl, heteroalicyclic, heteroaryl, and amine,
- provided that at least one of R41 and R42 is a bulky rigid alkyl.
Dependencies are inferred from the claim text.