Process for preparing cyclic carbonates with an exocyclic vinylidene group

A process for preparing at least one cyclic carbonate I selected from the group consisting of

• a compound of formula Ia, a compound of formula Ib, a mixture of the compound of formula Ia and the compound of formula Ib, and a compound of formula I-bis;
• wherein
• A is a bridging group selected from the group consisting of:
• ˜CH2—O—CH2-1,4-phenylene-CH2—O—CH2—;
• —CH2—O—C(═O)—NH—1,4-toluylene-NH—C(═O)—O—CH2—;
• —CH2—O—CH2—CH(OH)—CH2—O—(CH2)—O—CH—CH(OH)—CH2—O—CH2—;
• —CH2—O—CH2—CH(OH)—CH2—O-1,4-phenylene-C(CH3)2-1,4-phenylene-O—CH2—CH(OH)—CH2—O—CH2—;
• and —CH2—(OCH2CH2)3—O—CH2—;
• and
• is —CH2—O—R14,
• wherein
• R14 is selected from the group consisting of hydrogen;
• C1-C4-alkyl carrying 1, 2, or 3 radicals R15;
• —C(═O)R16, and C3-C6-cycloalkyl carrying 1, 2, or 3 radicals R17;
• wherein
• R15 is selected from the group consisting of OH, C1-C4-alkoxy, phenyl, and a 3-, 4-, 5-, or 6-membered saturated heterocyclic ring containing 1 or 2 oxygen atoms as ring member;
• R16 is selected from the group consisting of C1-C6-alkyl, C2-C6-alkenyl, C1-C4-alkoxy, and —NR18R19, wherein R18 is hydrogen or C1-C4-alkyl and R19 is selected from the group consisting of hydrogen, C1-C4-alkyl, C1-C4-alkyl substituted by a group R20, and phenyl which may carry 1, 2, 3, 4, or 5 substituents selected from the group consisting of C1-C4-alkyl and C1-C4-alkoxy;
• wherein
• R20 is selected from the group consisting of —O—R21, —N(R13)—R21, —O—C(═O)—R21, —C(═O)—O—R21, —N(R13)—C(═O)—R21—C(═O)—N(R13)—R21, —O—C(═O)—O—R21, —O—C(═O)—N(R13)—R21—N(R13)—C(═O)—O—R21, and —N(R13)—C(═O)—N(R13)—R21, wherein each R21 is independently hydrogen, C1-C6-alkyl, or C2-C6-alkenyl, and wherein each R13 is independently hydrogen or C1-C10-alkyl;
• and
• R17 is selected from the group consisting of —O—R21, —N(R13)—R21—O—C(═O)—R21, —C(═O)—O—R21, —N(R13)—C(═O)—R21, —C(═O)—N(R13)—R21, —O—C(═O)—O—R21, —O—C(═O)—N(R13)—R21, —N(R13)—C(═O)—O—R21, and —N(R13)—C(═O)—N(R13)—R21, wherein each R21 is independently hydrogen, C1-C6-alkyl, or C2-C6-alkenyl, and wherein each R13 is independently hydrogen or C1-C10-alkyl;
• and
• the process comprising;
• a) reacting a proparoyl alcohol with carbon dioxide, to obtain a reaction mixture,
• wherein, if the at least one cyclic carbonate I is the compound of formula Ia, the compound of formula Ib, or the mixture of the compound of formula Ia and the compound of formula Ib, the propargyl alcohol is a compound of formula II
• wherein R1 is as defined above,
• or
• if the at least one cyclic carbonate I is the compound of the formula I-bis,
• the propargyl alcohol is the compound of the formula II, in which R1 is —CH2—O—R14, wherein R14 is as defined above, or the propargyl alcohol is a compound of the formula II-bis
• wherein A is as defined above;
• wherein the reaction is carried out in at least one organic solvent L1 or in a solvent mixture containing the at least one organic solvent L1 and at least one organic solvent L2;
• wherein the at least one organic solvent L1 has a higher polarity than the at least one organic solvent L2, and wherein the at least one organic solvent L1 and the at least one organic solvent L2 have a miscibility gap at least between 2° and 30° C.;
• wherein the reaction is carried out in the presence of a silver catalyst Ag1 comprising at least one bulky ligand and a carboxylate ligand,
• wherein the at least one bulky ligand is at least one selected from the group consisting of a compound of formulae A to W and a mixture thereof:
• wherein Me is methyl, Cy is cyclohexyl, i-Pr is isopropyl, Ph is phenyl, and t-Bu is tert-butyl;
• and
• wherein the carboxylate ligand is according to formula V
• wherein
• R6 is selected from the group consisting of C8-C18-alkyl and C2-C4-alkyl carrying a cyclohexyl ring;
• b1) in case that a) has not been carried out in the presence of the at least one solvent L2:
• adding the at least one solvent L2 to the reaction mixture obtained in a);
• or
• b2) in case that a) has been carried out in the presence of the at least one solvent L2:
• optionally, adding an additional amount of the at least one solvent L2 to the reaction mixture obtained in a);
• c) subjecting the reaction mixture obtained in a), b1), or b2) to a phase separation to obtain a product phase containing the at least one cyclic carbonate I and the at least one solvent L1, and a catalyst phase containing the silver catalyst and the at least one solvent L2;
• and
• d) if desired, isolating the at least one cyclic carbonate I from the product phase.