Synthesis of terminal alkenes from internal alkenes and ethylene via olefin metathesis

A method for synthesizing a metathesis reaction product having a terminal olefin, the method comprising contacting, in the presence of a metathesis catalyst, an olefinic substrate comprised of at least one internal olefin with ethylene, wherein the catalyst is present in an amount that is less than about 1000 ppm relative to the amount of the olefinic substrate, and wherein the metathesis catalyst has the structure of formula (IIa):

• wherein:
• M is Ru;
• X1 and X2 are anionic ligands;
• R1 is selected from the group consisting of hydrogen, hydrocarbyl, substituted hydrocarbyl, heteroatom-containing hydrocarbyl, and substituted heteroatom-containing hydrocarbyl;
• Q is selected from the group consisting of heteroatom-containing hydrocarbylene and substituted heteroatom-containing hydrocarbylene, wherein M is connected to a heteroatom, wherein a five or six member ring is formed with M and the heteroatom, and wherein two or more substituents on adjacent atoms within Q may be taken together to form an additional, optionally substituted cyclic structure;
• n1 is zero or 1;
• L1 has the structure of formula (IIIc):
• L3 is a neutral electron donating ligand;
• wherein Ar1 and Ar2 are independently aryl substituted with at least one group selected from the group consisting of C2-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C5-C12 aryl, C6-C12 aralkyl, and C6-C12 alkaryl;
• α is an optional double bond;
• and R13, R14, R15, and R16 are independently selected from the group consisting of hydrogen, hydrocarbyl, substituted hydrocarbyl, heteroatom-containing hydrocarbyl, and substituted heteroatom-containing hydrocarbyl, wherein any two or more of Ar1, Ar2, R13, R14, R15, and R16 may be taken together to form a cyclic group, and provided that R14 and R16 are not present if α is present.

A method for synthesizing a metathesis reaction product having a terminal olefin, the method comprising contacting, in the presence of a metathesis catalyst, an olefinic substrate comprised of at least one internal olefin with ethylene, wherein the catalyst is present in an amount that is less than about 1000 ppm relative to the amount of the olefinic substrate, and wherein the metathesis catalyst has the structure of formula (II):

• wherein:
• M is Ru;
• X1 and X2 are anionic ligands;
• R1 and R2 are independently selected from the group consisting of hydrogen, hydrocarbyl, substituted hydrocarbyl, heteroatom-containing hydrocarbyl, and substituted heteroatom-containing hydrocarbyl;
• n1 is zero or 1;
• n2 is 1;
• L2 is selected from the group consisting of Py, PPh3, and PCy3;
• L3 is a neutral electron donating ligand;
• and
• L1 has the structure of formula (IIIc):
• wherein Ar1 and Ar2 are independently aryl substituted with at least one group selected from the group consisting of C2-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C5-C12 aryl, C6-C12 aralkyl, and C6-C12 alkaryl;
• α is an optional double bond;
• and R13, R14, R15, and R16 are independently selected from the group consisting of hydrogen, hydrocarbyl, substituted hydrocarbyl, heteroatom-containing hydrocarbyl, and substituted heteroatom-containing hydrocarbyl, wherein any two or more of Ar1, Ar2, R13, R14, R15, and R16 may be taken together to form a cyclic group, and provided that R14 and R16 are not present if α is present.

A method for synthesizing a metathesis product having a terminal olefin, the method comprising contacting, in the presence of a metathesis catalyst, an olefinic substrate comprised of at least one internal olefin with ethylene, wherein the catalyst is present in an amount that is less than about 1000 ppm relative to the amount of the olefinic substrate, and wherein the metathesis catalyst has the structure of formula (XII):

• wherein:
• t is zero;
• M is Ru;
• X1 and X2 are anionic ligands;
• Z3 is a cationic moiety selected from the group consisting of P(R2)3 and N(R2)3;
• R1 and R2 are independently selected from the group consisting of hydrogen, hydrocarbyl, substituted hydrocarbyl, heteroatom-containing hydrocarbyl, and substituted heteroatom-containing hydrocarbyl;
• Y is a non-coordinating anion;
• and
• L1 is a carbene ligand with the structure of formula (IIIc):
• wherein Ar1 and Ar2 are independently aryl substituted with at least one group selected from the group consisting of C2-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, C6-C12 aryl, C6-C12 aralkyl, and C6-C12 alkaryl;
• α is an optional double bond;
• and R13, R14, R15, and R16 are independently selected from the group consisting of hydrogen, hydrocarbyl, substituted hydrocarbyl, heteroatom-containing hydrocarbyl, and substituted heteroatom-containing hydrocarbyl, wherein any two or more of Ar1, Ar2, R13, R14, R15, and R16 may be taken together to form a cyclic group, and provided that R14 and R16 are not present if α is present.