Highly

1. A metal complex having the structure:

wherein:

M is W;

R 1 is aryl, heteroaryl, alkyl, heteroalkyl, optionally substituted;

R 2 and R 3 can be the same or different and are hydrogen, alkyl, alkenyl, heteroalkyl, heteroalkenyl, aryl, or heteroaryl, optionally substituted; and

R 4 and R 5 can be the same or different and are alkyl, heteroalkyl, aryl, heteroaryl, silylalkyl, or silyloxy, optionally substituted;

one of R 4 and R 5 is a ligand containing oxygen bound to M, optionally substituted, and the other is a ligand containing nitrogen bound to M, optionally substituted;

the ligand containing oxygen bound to M is substituted —O-aryl wherein substituents positioned in close proximity to the metal center are sterically large groups, wherein the ligand containing oxygen bound to M is substituted —O-aryl wherein the aryl group is 1,2,3,4-tetrahydronaphthyl or naphthyl, or the ligand containing oxygen bound to M is:

wherein R 7 is aryl, heteroaryl, alkyl, or heteroalkyl, optionally substituted;

R 8 is hydrogen, —OH, halogen, alkyl, heteroalkyl, aryl, heteroaryl, acyl, acyloxy, or —OP, optionally substituted; or,

together R 7 and R 8 are joined to form a ring, optionally substituted;

R 9 is —OH, which is deprotonated upon coordination to M;

R 19 is alkyl, heteroalkyl, aryl, heteroaryl, or acyl, optionally substituted;

each R 11 , R 12 , R 13 , and R 14 can be the same or different and is aryl, heteroaryl, alkyl, heteroalkyl, or acyl, optionally substituted; or,

together R 11 and R 12 are joined to form a ring, optionally substituted; or

together R 13 and R 14 are joined to form a ring, optionally substituted; and

P is a protecting group; or

the ligand containing oxygen bound to M is selected from

wherein each R 7 and R 8 can be the same or different and is hydrogen, halogen, alkyl, alkoxy, aryl, acyl, or a protecting group, optionally substituted;

R 10 is alkyl, heteroalkyl, aryl, heteroaryl, or acyl, optionally substituted;

each R 11 , R 12 , R 13 , and R 14 can be the same or different and is aryl, heteroaryl, alkyl, heteroalkyl, or acyl, optionally substituted; or,

together R 11 and R 12 are joined to form a ring, optionally substituted; or,

together R 13 and R 14 are joined to form a ring, optionally substituted;

R 15 is alkyl, aryl, or a protection group, optionally substituted;

R 16 is hydrogen or an amine protecting group;

X can be any non-interfering group;

each Z can be the same or different and is (CH 2 ) m , N, O, optionally substituted;

n is 0-5;

m is 1-4; and

the —OH group is deprotonated upon coordination to M;

a sterically large group is an optionally substituted group selected from tert-butyl, isopropyl, adamantyl, and naphthyl, or a substituted phenyl group.

2. The metal complex of claim 1 , wherein the ligand containing oxygen bound to M is substituted —O-aryl, and substituents positioned in close proximity to the metal center are alkylaryl.

3. The metal complex of claim 1 , wherein the ligand containing oxygen bound to M is 3,3′-di-tert-butyl-5,5′,6,6′-tetramethyl-2′-(trimethylsilyloxy)biphenyl-2-olate (BiphenTMS), 2′-(tert-butyldimethylsilyloxy)-3-mesityl-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl-2-olate (MesBitet), 3,3′-dimesityl-2′-(tert-butyldimethylsilyloxy)-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl-2-olate (Mes 2 Bitet), or 3,3′-dimesityl-2′-methoxy-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl-2-olate (Mes 2 BitetOMe).

4. The metal complex of claim 1 , wherein the ligand containing oxygen bound to M is

5. The metal complex of claim 1 , wherein the ligand containing oxygen bound to M is selected from

6. The metal complex of claim 5 , wherein R 10 is tert-butyl, optionally substituted.

7. The metal complex of claim 5 , wherein R 10 is substituted phenyl.

8. The metal complex of claim 1 , wherein the nitrogen bound to M in the nitrogen-containing ligand is a ring atom of a heteroaryl group.

9. The metal complex of claim 1 , wherein the ligand containing nitrogen bound to M is selected from the group consisting of pyrrolyl, pyrazolyl, pyridinyl, pyrazinyl, pyrimidinyl, imidazolyl, triazolyl, tetrazolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, indolyl, indazolyl, carbazolyl, morpholinyl, piperidinyl, and oxazinyl, all optionally substituted.

10. The metal complex of claim 1 , wherein the ligand containing nitrogen bound to M is pyrrolyl, optionally substituted.

11. The metal complex of claim 1 , wherein the ligand containing nitrogen bound to M has the structure:

wherein each R 6 can be the same or different and is hydrogen, alkyl, heteroalkyl, aryl, or heteroaryl, optionally substituted; and

X may be present or absent and is any non-interfering group.

12. The metal complex of claim 1 , wherein the alkylidene group is mono-substituted in that one of R 2 and R 3 is hydrogen, and the other is alkyl, heteroalkyl, aryl, or heteroaryl, optionally substituted.

13. The metal complex of claim 1 , wherein R 1 is substituted phenyl.

14. The metal complex of claim 1 , wherein the metal complex is isolated.

15. A metal complex selected from the group consisting of M(NAr)(Pyr)(C 3 H 6 )(OHIPT), M(NAr)(CHCMe 2 Ph)(Pyr)(BiphenTMS), M(NAr)(CHCMe 2 Ph)(Me 2 Pyr)(Br 2 Bitet), wherein M=W, M(NAr)(CHCMe 2 Ph)(Me 2 Pyr)(MesBitet), W(NAr)(CHCMe 2 Ph)(Me 2 Pyr)(OPhPh 4 ), M(NAr)(CHCMe 2 Ph)(Pyr)((Trip) 2 BitetTMS), M(NAr Cl )(CHCMe 3 )(Pyr)(BiphenTMS), M(NAr Cl )(CHCMe 3 )(Me 2 Pyr)(OSi(TMS) 3 ), M(NAr Cl )(CHCMe 3 )(Me 2 Pyr)(OPhPh 4 ), M(NAr Cl )(CHCMe 3 )(Me 2 Pyr)(HIPTO), M(NAr Cl )(CHCMe 3 )(Me 2 Pyr)(HIPTO), M(NAr Cl )(CHCMe 3 )(Me 2 Pyr)(Br 2 Bitet), M(NAr Cl )(CHCMe 3 )(Me 2 Pyr)(MesBitet), M(NAr Cl )(CHCMe 3 )(Pyr)(Mes 2 Bitet), M(NAd)(CHCMe 2 Ph)(Me 2 Pyr)(OSi(TMS) 3 ), M(NAd)(CHCMe 2 Ph))(Me 2 Pyr)(HIPTO), wherein M=W, M(NAd)(CHCMe 2 Ph)(Me 2 Pyr)(MesBitet), M(NAr)(Pyr)(CHR 2 )(OHIPT), M(NAr′)(CHCMe 2 Ph)(Me 2 Pyr)(OSi(TMS) 3 ), M(NAr′)(CHCMe 2 Ph)(Me 2 Pyr)(OPhPh 4 ), M(NAr)(CHCMe 2 Ph)(Me 2 Pyr)(HIPTO), M(NAr′)(CHCMe 2 Ph)(Me 2 Pyr)(Br 2 Bitet), M(NAr′)(CHCMe 2 Ph)(Pyr)(MesBitet), M(NAr′)(CHCMe 2 Ph)(Me 2 Pyr)(MesBitet), M(NAr′)(CHCMe 2 Ph)(Pyr)(Mes 2 BitetOMe), or M(NAr′)(CHCMe 2 Ph)(Pyr)(Mes 2 Bitet), wherein M is Mo or W, Ar is 2,6-diisopropylphenyl, Ar Cl is 2,6-dichlorophenyl, Ar′ is 2,6-dimethyphenyl, Ad is 1-admantyl, Mes is mesityl, Me 2 Pyr is 2,5-dimethylpyrrolide, Pyr is pyrrolide, TBS is dimethyl-t-butylsilyl, Trip is 2,4,6-triisopropylphenyl, HIPTO is hexaisopropylterphenolate, OSi(TMS) 3 is 1,1,1,3,3,3-hexamethyl-2-(trimethylsilyl)trisilan-2-olate, Biphen is 3,3′-di-tert-butyl-5,5′,6,6′-tetramethylbiphenyl-2,2′-diol, BiphenTMS is 3,3′-di-tert-butyl-5,5′,6,6′-tetramethyl-2′-(trimethylsilyloxy)biphenyl-2-olate, Bitet is 5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl-2,2′-diol, Trip 2 Bitet is 3,3′-bis(2,4,6-triisopropylphenyl)-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl-2,2′-diol, Trip 2 BitetTMS is 3,3′-bis(2,4,6-triisopropylphenyl)-2′-(trimethylsilyloxy)-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl-2-olate, Br 2 Bitet is 3,3′-dibromo-2′-(tert-butyldimethylsilyloxy)-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl-2-olate, MesBitet is 2′-(tert-butyldimethylsilyloxy)-3-mesityl-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl-2-olate, Mes 2 Bitet is 3,3′-dimesityl-2′-(tert-butyldimethylsilyloxy)-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl-2-olate, and Mes 2 BitetOMe is 3,3′-dimesityl-2′-methoxy-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl-2-olate.

16. A method for performing a metathesis reaction, comprising providing a metal complex of claim 1 .