Stable silylating reagents

Abstract

The present disclosure is directed to methods of silylating organic substrates containing C—H or O—H bonds. In some embodiments, the methods use compositions that are derived from the preconditioning of mixtures of hydrosilanes or organodisilanes with bases, including metal hydroxide, metal alkoxide, metal silanoates, potassium amides, and/or graphitic potassium bases.

What is claimed: 
     
         1 . A method of silylating an organic substrate having a C—H bond or an O—H bond, the method comprising contacting the organic substrate with a mixture of:
 (a) a precursor hydrosilane or organodisilane; and 
 (b) a base comprising a potassium silanolate, a potassium amide, rubidium hydroxide, a rubidium alkoxide, a rubidium silanolate, cesium hydroxide, a cesium alkoxide, a cesium silanolate, a graphitic potassium (KC 8 ), or a combination thereof; 
 
       wherein the contacting results in the formation of a C—Si bond in the position previously occupied by the C—H bond or an O—Si bond in the position previously occupied by the O—H bond, respectively; and 
       wherein the C—H bond is:
 (a) located on a heteroaromatic moiety; 
 (b) located on an alkyl, alkoxy, or alkylene moiety positioned alpha to an aryl or heteroaryl moiety; 
 (c) an alkynyl C—H bond; or 
 (d) a terminal olefinic C—H bond. 
 
     
     
         2 . The method of  claim 1  wherein the mixture is preconditioned before contacting with the organic substrate, the preconditioning comprising holding the mixture comprising the precursor hydrosilane and the base at one or more temperatures in a range of from about 25° C. to about 125° C. for a time in a range of from about 30 minutes to about 24 hours. 
     
     
         3 . The method of  claim 1 , wherein the mixture further comprises a solvent. 
     
     
         4 . The method of  claim 3 , wherein the solvent is tetrahydrofuran or 2-methyltetrahydrofuran. 
     
     
         5 . The method of  claim 1 , wherein the base comprises rubidium hydroxide, or cesium hydroxide. 
     
     
         6 . The method of  claim 1 , wherein the base comprises a potassium amide. 
     
     
         7 . The method of  claim 1 , wherein the base comprises a rubidium alkoxide, or a cesium alkoxide. 
     
     
         8 . The method of  claim 1 , wherein the base comprises a potassium silanoate, a rubidium silanolate, or a cesium silanolate. 
     
     
         9 . The method of  claim 1 , wherein the base comprises a graphitic potassium (KC 8 ). 
     
     
         10 . The method of  claim 1 , wherein the precursor hydrosilane is of the Formula (I) or Formula (II) or the precursor organodisilane is of the Formula (III):
   (R) 3−m Si(H) m+1   (I)
     (R) 3−m (H) m Si—Si(R) 2−m (H) m+1   (II)
     (R′) 3 Si—Si(R′) 3   (III)
   where: m is independently 0, 1, or 2; and each R and R′ are independently optionally substituted C 1-24  alkyl or heteroalkyl, optionally substituted C 2-24  alkenyl, optionally substituted C 2-24  alkynyl, optionally substituted C 6-12  aryl, C 3-12  heteroaryl, optionally substituted C 7-13  alkaryl, optionally substituted C 4-12  heteroalkaryl, optionally substituted C 7 -13 aralkyl, optionally substituted C 4-12  heteroaralkyl, and, if substituted, the substituents may be phosphonato, phosphoryl, phosphanyl, phosphino, sulfonato, C 1 -C 20  alkylsulfanyl, C 5 -C 20  arylsulfanyl, C 1 -C 20  alkylsulfonyl, C 5 -C 20  arylsulfonyl, C 1 -C 20  alkylsulfinyl, 5 to 12 ring-membered arylsulfinyl, sulfonamido, amino, imino, nitro, nitroso, hydroxyl, C 1 -C 20  alkoxy, C 5 -C 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, silanyl, siloxazanyl, boronato, boryl, or halogen, or a metal-containing or metalloid-containing group, where the metalloid is Sn or Ge, where the substituents may optionally provide a tether to an insoluble or sparingly soluble support media comprising alumina, silica, or carbon.   
     
     
         11 . The method of  claim 1 , wherein the at least one hydrosilane is (R) 3 SiH or (R) 2 SiH 2 , where R is independently at each occurrence C 1-6  alkyl, phenyl, tolyl, or pyridinyl. 
     
     
         12 . The method of  claim 1 , wherein the organic substrate contains an —OH bond and the contacting results in the formation of an O—Si bond in the position previously occupied by the O—H bond. 
     
     
         13 . The method of  claim 1 , wherein the organic substrate contains a C—H bond, wherein the C—H bond is:
 (a) located on the heteroaromatic moiety; or 
 (b) located on an alkyl, alkoxy, or alkylene moiety positioned alpha to an aryl or heteroaryl moiety; and 
 
       the contacting results in the formation of a C—Si bond in the position previously occupied by the C—H bond. 
     
     
         14 . The method of  claim 1 , wherein the organic substrate contains a C—H bond, wherein the C—H bond is an alkynyl C—H bond and the contacting results in the formation of a C—Si bond in the position previously occupied by the C—H bond. 
     
     
         15 . The method of  claim 1 , wherein the organic substrate contains a C—H bond, wherein the C—H bond is a terminal olefinic C—H bond and the contacting results in the formation of a C—Si bond in the position previously occupied by the C—H bond.