Synthesis and stabilization of neutral compounds with homonuclear bonds

1. A stable neutral compound of formula:

wherein:

R 1 is a persistent carbene selected from the group consisting of imidazole-2-ylidenes, triazole-5-ylidenes, cyclic diaminocarbenes, acyclic diaminocarbenes, heteroaminocarbenes, and combinations thereof;

R 2 and R 3 are, independently of each other, absent or are selected from the group consisting of: H, F, Br, Cl, I, and combinations thereof;

and E is B, Si, or P;

with the proviso that:

when E is B, is ═, R 2 is absent and R 3 is H, F, Br, or Cl;

when E is B and is ═, R 2 and R 3 are, independently of each other, H, F, Br, or Cl;

when E is Si, and is ═, both R 2 and R 3 are absent;

when E is Si, and is —, R 2 is absent and R 3 is H, F, Br, Cl, or I;

when E is P and is —, both R 2 and R 3 are absent.

2. The compound of claim 1 , wherein R 1 is the carbene selected from the group consisting of :C{N(SiR x 3 )CH} 2 , wherein R x is methyl, tert-butyl, monoalkylaryl, dialkylaryl, trialkylaryl, dialkylamido, :C{N(2,6-Pr i 2 C 6 R y 3 )CH} 2 , :C(NHCH) 2 , :C{N(Pr i )C(CR y 3 )} 2 , :C{N(2,4,6-Me 3 C 6 R y 2 )CH} 2 , wherein R y is, independently, H, F, Br, Cl, or I, and combinations thereof.

3. The compound of claim 2 , represented by the formula:

4. A method of making a stable neutral compound of a formula:

wherein:

R 1 is a persistent carbene selected from the group consisting of imidazole-2-ylidenes, triazole-5-ylidenes, cyclic diaminocarbenes, acyclic diaminocarbenes, heteroaminocarbenes, and combinations thereof;

R 2 and R 3 are, independently of each other, absent or are selected from the group consisting of: H, F, Br, Cl, I, and combinations thereof;

and E is B, Si, or P;

with the proviso that:

when E is B, and is ═, R 2 is absent and R 3 is H, F, Br, or Cl;

when E is B and is ═, R 2 and R 3 are, independently of each other, H, F, Br, or Cl;

when E is Si, and is ═, both R 2 and R 3 are absent;

when E is Si, and is —, R 2 is absent and R 3 H, F, Br, Cl, or I;

when E is P and is —, both R 2 and R 3 are absent;

said method comprising:

(a) reacting a compound of the formula

wherein R 4 and R 5 are, independently of each other, selected from the group consisting of: H, F, Br, Cl, and I,

with R 1 , thus forming:

(b) reacting a product formed in (a) with a reducing agent in a solvent selected from the group consisting of dimethyl ether, diethyl ether, THF, dioxane, dimethoxyethane, methoxybenzene, and ethylene oxide, and combinations thereof; and

(c) isolating

5. The method of claim 4 , wherein the reducing agent is selected from the group consisting of KC 8 , LiAlH 4 , NaBH 4 , DIBAL, Na(Hg), Na—K alloy, K(Hg), LiH, alkali and alkali earth metals, nascent hydrogen, and combinations thereof.

6. The method of claim 5 , wherein the reducing agent is KC 8 .

7. The method of claim 4 , wherein the ratio of

wherein R 2 , R 3 , R 4 , and R 5 are, independently of each other, selected from the group consisting of: H, F, Br, Cl, and I, to the reducing agent is about 1 to about 10.

8. The method of claim 4 , wherein the ratio of

wherein R 2 , R 3 , R 4 , and R 5 are, independently of each other, selected from the group consisting of: H, F, Br, Cl, and I, to the reducing agent is about 1 to about 6.

9. The method of claim 4 , wherein the ratio of

wherein R 2 , R 3 , R 4 , and R 5 are, independently of each other, selected from the group consisting of: H, F, Br, Cl, and I, to the reducing agent is about 1 to about 5.

10. The method of claim 4 , wherein the ratio of

wherein R 2 , R 3 , R 4 , and R 5 are, independently of each other, selected from the group consisting of: H, F, Br, Cl, and I, to the reducing agent is about 1 to about 4.

11. The method of claim 10 , wherein the ratio between R 1 SiCl 4 , wherein R 1 is :C{N(2,6-Pr i 2 C 6 H 3 )CH} 2 , and KC 8 is 1:4.

12. The method of claim 9 , wherein the ratio between R 1 BBr 3 , wherein R 1 is :C{N(2,6-Pr i 2 C 6 H 3 )CH} 2 , and KC 8 is 1:5.4.

13. The method of claim 9 , wherein the ratio between R 1 BBr 3 , wherein R 1 is :C{N(2,4,6-Me 3 C 6 H 2 )CH} 2 , and KC 8 is 1:5.