Process and intermediate compounds for the preparation of difluorovinylsilane insecticidal and acaricidal agents

A process for the preparation of a a difluoro-vinylsilane compound of the formula

• wherein
• Ar is phenyl, optionally substituted with any combination of from one to three halogen, C1-C4alkyl, C1-C4haloalkyl, C1-C4alkoxy, C1-C4haloalkoxy, C(O)R2 or S(O),R3 groups,
• 1- or 2-naphthyl, optionally substituted with any combination of from one to three halogen, C1-C4alkyl, C1-C4haloalkyl, C1-C4alkoxy, C1-C4haloalkoxy, C(O)R2 or S(O)nR3 groups, or
• a 5- or 6-membered heteroaromatic ring, optionally substituted with any combination of from one to three halogen, C1-C4alkyl, C1-C4haloalkyl, C1-C4alkoxy, C1-C4haloalkoxy, C(O)R2 or S(O)nR3 groups;
• R and R1 are each independently C1-C4alkyl or C3-C5cycloalkyl;
• Ar1 is phenoxyphenyl, optionally substituted with any combination of from one to five halogen, C1-C4alkyl, C1-C4haloalkyl, C1-C4alkoxy, C1-C4haloalkoxy or C(O)R4 groups,
• phenyl, optionally substituted with any combination of from one to five halogen, C1-C4alkyl, C1-C4haloalkyl, C1-C4alkoxy, C1-C4haloalkoxy or C(O)R4 groups,
• biphenyl, optionally substituted with any combination of from one to five halogen, C1-C4alkyl, C1-C4haloalkyl, C1-C4alkoxy, C1-C4haloalkoxy or C(O)R4 groups,
• phenoxypyridyl, optionally substituted with any combination of from one to five halogen, C1-C4alkyl, C1-C4haloalkyl, C1-C4alkoxy, C3-C4haloalkoxy or C(O)R4 groups,
• benzylpyridyl, optionally substituted with any combination of from one to five halogen, C1-C4alkyl, C1-C4haloalkyl, C1-C4alkoxy, C1-C4haloalkoxy or C(O)R4 groups,
• benzylphenyl, optionally substituted with any combination of from one to five halogen, C1-C4alkyl, C1-C4haloalkyl, C1-C4alkoxy, C1-C4haloalkoxy or C(O)R4 groups,
• 1- or 2-naphthyl, optionally substituted with any combination of from one to three halogen, C1-C4alkyl, C1-C4haloalkyl, C1-C4alkoxy, C1-C4haloalkoxy or C(O)R4 groups, or
• a 5- or 6-membered heteroaromatic ring optionally substituted with any combination of from one to three halogen, C1-C4alkyl, C1-C4haloalkyl, C1-C4alkoxy, C1-C4haloalkoxy or C(O)R4 groups;
• n is an integer of 0, 1 or 2;
• R2 and R4 are each independently C1-C4alkyl, benzyl or phenyl;
• and
• R3 is C1-C4alkyl or C1-C4haloalkyl;
• and the fluorine atoms attached to the double bond are trans with respect to each other, which process comprises:
• (a) reacting a vinylorganometallic compound having the structural formula
• F2C=CFM
• wherein M is Cu, Li, ZnX or CdX, and X is Cl, Br or I with an α-(halomethyl)aryl compound having the structural formula
• YCH2Ar1
• wherein Y is Cl, Br or I, and Ar1 is as described above to form a 3-aryl-1,1,2-trifluoro-1-propene compound having the structural formula
• F2C=CFCH2Ar1;
• (b) reacting the 3-aryl-1,1,2-trifluoro-1-propene compound with a reducing agent to form a 3-aryl-1,2-difluoro-1-propene compound having the structural formula
• wherein the fluorine atoms attached to the double bond are predominately trans with respect to each other;
• (c) reacting the 3-aryl-1,2-difluoro-1-propene compound with a lithium base to form a 3-aryl-1,2-difluoro-1-propenyllithium compound having the structural formula
• wherein the fluorine atoms attached to the double bond are predominately trans with respect to each other;
• and
• (d) reacting the 3-aryl-1,2-difluoro-1-propenyl-lithium compound with an arylchlorosilane compound having the structural formula
• wherein Ar, R and R1 are as described above.

A compound having the structural formula

• wherein
• W is H, F or Li;
• Ar1 is phenoxyphenyl optionally substituted with any combination of from one to five halogen, C1-C4alkyl, C1-C4haloalkyl, C1-C4alkoxy, C1-C4haloalkoxy or C(O)R4 groups,
• phenyl optionally substituted with any combination of from one to five halogen, C1-C4alkyl, C1-C4haloalkyl, C1-C4alkoxy, C1-C4haloalkoxy or C(O)R4 groups,
• biphenyl optionally substituted with any combination of from one to five halogen, C1-C4alkyl, C1-C4haloalkyl, C1-C4alkoxy, C1-C4haloalkoxy or C(O)R4 groups,
• phenoxypyridyl optionally substituted with any combination of from one to five halogen, C1-C4alkyl, C1-C4haloalkyl, C1-C4alkoxy, C1-C4haloalkoxy or C(O)R4 groups,
• benzylpyridyl optionally substituted with any combination of from one to five halogen, C1-C4alkyl, C1-C4haloalkyl, C1-C4alkoxy, C1-C4haloalkoxy or C(O)R4 groups,
• benzylphenyl optionally substituted with any combination of from one to five halogen, C1-C4alkyl, C1-C4haloalkyl, C,.-C4alkoxy, C1-C4haloalkoxy or C(O)R4 groups,
• 1- or 2-naphthyl optionally substituted with any combination of from one to three halogen, C1-C4alkyl, C1-C4haloalkyl, C1-C4alkoxy, C1-C4haloalkoxy or C(O)R4 groups, or
• a 5- or 6-membered heteroaromatic ring optionally substituted with any combination of from one to three halogen, C1-C4alkyl, C1-C4haloalkyl, C1-C4alkoxy, C1-C4haloalkoxy or C(O)R4 groups;
• and
• R4 is C1-C4alkyl, benzyl or phenyl;
• and
• when W is H or Li, the fluorine atoms attached to the double bond are predominately trans with respect to each other.