Silylations of aromatic substrates with base-activated organosilanes

Patent metadata

Field	Value
Publication number	US-10927065-B2
Application number	US-201815889295-A
Country	US
Kind code	B2
Filing date	Feb 6, 2018
Priority date	Oct 2, 2012
Publication date	Feb 23, 2021
Grant date	Feb 23, 2021

Abstract

The present disclosure describes methods for silylating aromatic organic substrates, and associated chemical systems, said methods comprising or consisting essentially of contacting the aromatic organic substrate with a mixture of (a) at least one organosilane and (b) at least one strong base, under conditions sufficient to silylate the aromatic substrate.

First claim

The invention claimed is:

1. A method for silylating aromatic organic substrates, the method comprising contacting an organic substrate comprising an aromatic moiety with a mixture comprising (a) at least one hydrosilane and (b) a strong base comprising a potassium alkoxide, cesium alkoxide, potassium hydride, or potassium bis(trimethylsilyl)amide, under conditions sufficient to silylate the organic substrate, the method resulting in the formation of a silylated organic substrate,
wherein the at least one hydrosilane is a hydrosilane of Formula (I):
(R) 4-m Si(H) m   (I)

where m is 1, 2, or 3; and
each R is independently optionally substituted C 1-12 alkyl or C 1-12 heteroalkyl, optionally substituted C 6-20 aryl or C 5-20 heteroaryl, optionally substituted C 7-30 alkaryl or C 6-30 heteroalkaryl, optionally substituted C 7-30 aralkyl or C 6-30 heteroaralkyl, wherein each optional substitutents is independently phosphonato, phosphoryl, phosphanyl, phosphino, sulfonato, C 1 -C 20 alkylsulfanyl, C 6-20 arylsulfanyl, C 1 -C 20 alkylsulfonyl, C 6-20 arylsulfonyl, C 1 -C 20 alkylsulfinyl, C 6-20 arylsulfinyl, sulfonamido, amino, amido, imino, nitro, nitroso, hydroxyl, C 1 -C 20 alkoxy, C 6-20 aryloxy, C 2 -C 20 alkoxycarbonyl, C 5 -C 20 aryloxycarbonyl, carboxyl, carboxylato, mercapto, formyl, C 1 -C 20 thioester, cyano, cyanato, thiocyanato, isocyanate, thioisocyanate, carbamoyl, epoxy, styrenyl, silyl, silyloxy, siloxazanyl, boronato, boryl, or halogen, or where the substituent optionally provides a tether to an insoluble or sparingly soluble support media comprising alumina, silica, or carbon; and
wherein the silylated organic substrate has a carbon-silicon bond in a position previously occupied by a carbon-hydrogen bond in the organic substrate.

2. The method of claim 1 , wherein the carbon-silicon bond in the silylated organic substrate is in a position corresponding to a carbon-hydrogen bond on the aromatic moiety, unless:
(a) the organic substrate is a hydrocarbon comprising a carbocyclic aryl moiety having an alkyl substituent, in which case the silylated organic substrate has a carbon-silicon bond on a carbon of the alkyl substituent alpha to the carbocyclic aryl moiety; or
(b) the aromatic moiety is one having an alkylthioether substituent linked to a ring carbon atom of the aromatic ring moiety, in which case the silylated organic substrate has a carbon-silicon bond on the carbon alpha to the thioether sulfur; or
(c) the aromatic moiety is a pyridinyl moiety having alkyl substituents on one or both C2- and C6-positions, in which case the silylated organic substrate has a carbon-silicon bond on the carbon alpha to the pyridinyl ring; or
(d) the aromatic moiety is a heteroaryl moiety comprising a 5-membered heteroaryl ring having no C—H substituents in its C-2 or C-5 position and at least one alkyl substituent in the C-2 or C-5 position, in which case the silylated organic substrate has a carbon-silicon bond on the carbon alpha to the 5-membered heteroaryl ring.

3. The method of claim 1 , wherein the mixture and organic substrate are free of added transition-metal species.

4. The method of claim 1 , wherein the at least one hydrosilane comprises a hydrosilane of Formula (I):
(R) 4-m Si(H) m   (I)

where m is 1, 2, or 3; and
each R is independently optionally substituted C 1-12 alkyl or C 1-12 heteroalkyl, optionally substituted C 6-20 aryl or C 5-20 heteroaryl, optionally substituted C 7-30 alkaryl or C 6-30 heteroalkaryl, optionally substituted C 7-30 aralkyl or C 6-30 heteroaralkyl, wherein each optional substitutents is independently amino, amido, imino, nitro, nitroso, hydroxyl, C 1 -C 20 alkoxy, C 6-20 aryloxy, C 2 -C 20 alkoxycarbonyl, C 5 -C 20 aryloxycarbonyl, carboxyl, carboxylato, mercapto, formyl, C 1 -C 20 thioester, cyano, cyanato, thiocyanato, isocyanate, thioisocyanate, carbamoyl, epoxy, styrenyl, silyl, silyloxy, siloxazanyl, boronato, boryl, or halogen.

5. The method of claim 4 , wherein each R is independently C 1-6 alkyl.

6. The method of claim 4 , wherein the at least one hydrosilane comprises a hydrosilane of Formula (I), wherein m is 1 or 2, and each R is independently C 1 -C 6 alkyl, phenyl, tolyl, benzyl, phenethyl, or pyridinyl.

7. The method of claim 1 , wherein the strong base comprises a potassium alkoxide or cesium alkoxide.

8. The method of claim 7 , wherein the potassium alkoxide or cesium alkoxide comprises a C 1-12 linear or branched alkyl moiety or a C 5-10 aryl or heteroaryl moiety.

9. The method of claim 1 , wherein the strong base comprises potassium methoxide, potassium ethoxide, potassium propoxide or potassium butoxide.

10. The method of claim 1 , wherein the strong base is potassium tert-butoxide.

11. The method of claim 1 , wherein the strong base is potassium hydride.

12. The method of claim 1 , wherein the hydrosilane and the at least one strong base are present together at a molar ratio, with respect to one another, in a range of from 20:1 to 1:1.

13. The method of claim 1 , wherein the strong base and organic substrate are present together at a molar ratio, with respect to one another, in a range of from 0.01:1 to 0.9:1.

14. The method of claim 2 , wherein the organic substrate is a hydrocarbon comprising a carbocyclic aryl moiety having the alkyl substituent, and the silylated organic substrate has a carbon-silicon bond on the carbon of the alkyl substituent alpha to the carbocyclic aryl moiety.

15. The method of claim 14 , wherein the carbocyclic aryl moiety is a benzene, biphenyl, naphthalene, or anthracene ring structure having an alkyl substituent, wherein silylated organic substrate has a carbon-silicon bond on the alkyl substituent in a position alpha to the carbocyclic aryl moiety.

16. The method of claim 2 , wherein the aromatic moiety is one having an alkylthioether substituent linked to a ring carbon atom of the aromatic ring moiety, and the silylated organic substrate has a carbon-silicon bond on a carbon alpha to the thioether sulfur.

17. The method of claim 2 , wherein the organic substrate comprises an exocyclic aromatic C—X bond, where X is N or O, and the silylation occurs ortho to the exocyclic aromatic C—X bond.

18. The method of claim 1 , wherein the organic substrate comprises a heteroaryl moiety.

19. The method of claim 18 , wherein the organic substrate comprises an optionally substituted furan, pyrrole, thiophene, pyrazole, imidazole, benzofuran, benzopyrrole, benzothiophene, azaindole, dibenzofuran, xanthene, dibenzopyrrole, or a dibenzothiophene.

20. The method of claim 18 , wherein the organic substrate comprises a furan, pyrrole, thiophene, pyrazole, imidazole, triazole, isoxazole, oxazole, thiazole, isothiazole, oxadiazole, pyridine, pyridazine, pyrimidine, pyrazine, triazone, benzofuran, benzothiophene, isobenzofuran, isobenzothiophene, indole, isoindole, indolizine, indazole, azaindole, benzisoxazole, benzoxazole, quinoline, isoquinoline, cinnoline, quinazoline, naphthyridine, 2,3-dihydrobenzofuran, 2,3-dihydrobenzopyrrole, 2,3-dihydrobenzothiophene, dibenzofuran, xanthene, dibenzopyrol, or dibenzothiophene moiety.

21. The method of claim 1 , wherein the organic substrate comprises at least one of the following aromatic moieties:

where X is N—R″, O, or S;
Y is N(R″) 2 , O—R″, or S—R″;
p is 0 to 3;
R′ is alkyl, halo, alkoxy, aryloxy, aralkyloxy, alk

Assignees

• California Inst Of Techn

Inventors

• Grubbs Robert H
• Fedorov Alexey
• Toutov Anton
• Betz Kerry N

Classifications

• C10G45/02

  to eliminate hetero atoms without changing the skeleton of the hydrocarbon involved and without cracking into lower boiling hydrocarbons; Hydrofinishing · CPC title

• C07F7/0896

  Compounds with a Si-H linkage · CPC title

• C07C209/28 Primary

  by reduction with other reducing agents · CPC title

• C07C1/22 Primary

  by reduction · CPC title

• C07F7/081

  comprising at least one atom selected from the elements N, O, halogen, S, Se or Te · CPC title