Molybdenum oxo alkylidene compounds, methods of making the same and use thereof in metathesis reactions

A compound of formula I:

• wherein:
• one of R1 and R2 is H and the other is an optionally substituted group selected from:
• C1-20 aliphatic, C1-20 heteroaliphatic having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• phenyl;
• a 3-7 membered saturated or partially unsaturated carbocyclic ring;
• an 8-10 membered bicyclic saturated, partially unsaturated or aryl ring;
• a 5-6 membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• a 4-7 membered saturated or partially unsaturated heterocyclic ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• a 7-10 membered bicyclic saturated or partially unsaturated heterocyclic ring having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• or an 8-10 membered bicyclic heteroaryl ring having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• each of R3 and R4 is independently halogen, R, —N(R)2, —NRC(O)R, —NRC(O)OR, —NRC(O)N(R)2, —NRSO2R, —NRSO2N(R)2, —NROR, —OR, or an optionally substituted group selected from a 5-6 membered monocyclic heteroaryl ring having at least one nitrogen and 0-3 additional heteroatoms independently selected from nitrogen, oxygen, or sulfur, a 4-7 membered saturated or partially unsaturated heterocyclic ring having at least one nitrogen and 0-2 additional heteroatoms independently selected from nitrogen, oxygen, or sulfur, a 7-10 membered bicyclic saturated or partially unsaturated heterocyclic ring having at least one nitrogen and 0-4 additional heteroatoms independently selected from nitrogen, oxygen, or sulfur, or an 8-10 membered bicyclic heteroaryl ring having at least one nitrogen and 0-4 additional heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• or
• two R groups on the same nitrogen atom are taken together with the nitrogen to form an optionally substituted 3-12 membered saturated, partially unsaturated, or aryl ring having 0-5 additional heteroatoms not including the same nitrogen atom independently selected from nitrogen, oxygen, or sulfur;
• or:
• each R is independently hydrogen or an optionally substituted group selected from:
• C1-20 aliphatic, C1-20 heteroaliphatic having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• phenyl;
• a 3-7 membered saturated or partially unsaturated carbocyclic ring;
• an 8-10 membered bicyclic saturated, partially unsaturated or aryl ring;
• a 5-6 membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• a 4-7 membered saturated or partially unsaturated heterocyclic ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• a 7-10 membered bicyclic saturated or partially unsaturated heterocyclic ring having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• or an 8-10 membered bicyclic heteroaryl ring having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• each R5 is independently a monodentate ligand, or two R5 are taken together with their intervening atoms to form an optionally substituted bidentate group;
• n is 0, 1, or 2;
• or
• one of R3 or R4 is a covalent bond linking Mo to an oxidic solid support.