Efficient Pd(0)-Catalyzed Hydrosilylation of Alkynes with Triorganosilanes

Abstract

An electron-rich Pd(0) complex, a Pd₂(dba)₃·CHCl₃-tricyclohexylphosphine combination catalyzes highly efficient hydrosilylation of alkynes at room temperature with Ph₃SiH or Ph₂MeSiH without solvents. The regioselectivity of this process is higher than that with the conventional Pt(0)-catalyzed hydrosilyl­ation.

hydrosilylation - palladium - phosphine - alkyne - alkene

References

1a Hiyama T. Kusumoto T. In Comprehensive Organic Synthesis   Vol. 8:  Trost BM. Fleming I. Pergamon Press; Oxford: 1991.  Chap. 3.12.

1b Ojima I. Li Z. Zhu J. In The Chemistry of Organosilicon Compounds, Part 2   Vol. 2:  Rappoport Z. Apeloig Y. Wiley; Chichester: 1998.  Chap. 29.

1c Corey JY. In Advances in Silicon Chemistry   Larson GL. JAI; Greenwich: 1991.  p.355 

1d Marciniec B. Comprehensive Handbook on Hydrosilylation   Pergamon Press; Oxford: 1992. 

2 Recent examples of hydrosilylation with other catalysts. Ni catalysis: Maciejewski H. Marciniec B. Kownacki I. J. Organomet. Chem.  2000,  597:  175 

Ru catalysis:

3a Trost BM. Ball ZT. J. Am. Chem. Soc.  2001,  123:  12726 

3b Na Y. Chang S. Org. Lett.  2000,  2:  1887 

3c Katayama H. Taniguchi K. Kobayashi M. Sagawa T. Minami T. Ozawa F. J. Organomet. Chem.  2002,  645:  192 

Lewis acid catalysis:

4a Asao N. Sudo T. Yamamoto Y. J. Org. Chem.  1996,  61:  7654 

4b Sudo T. Asao N. Gevorgyan V. Yamamoto Y. J. Org. Chem.  1999,  64:  2494 

4c Yamamoto K. Takemae M. Synlett  1990,  259 

4d Rubin M. Schwier T. Gevorgyan N. J. Org. Chem.  2002,  67:  1936 

4e Song YS. Yoo BR. Lee GH. Jung IN. Organometallics  1999,  18:  3109 

4f Buriak JM. Allen MJ. J. Am. Chem. Soc.  1998,  120:  1339 

Radical Catalysis:

5a Miura K. Oshima K. Utimoto K. Bull. Chem. Soc. Jpn.  1993,  66:  2356 

5b Amrein S. Timmermann A. Studer A. Org. Lett.  2001,  3:  2357 

6a Ojima I. Yatabe M. Fuchikami T. J. Organomet. Chem.  1984,  260:  335 

6b Hydrosilylation with cationic palladium complexes has been reported, see: Winderhoefer RA. Vadera A. Cheruvu PK. Organometallics  1999,  18:  4614 

6c Pd-catalyzed hydrosilylation with dimerization of alkynes: Kawanami Y. Yamamoto K. Synlett  1995,  1232 

6d The Pd₂dba₃·CHCl₃-Cy₃P-catalyzed reaction of alkynes with PhSiH₃ has been reported, see: Yamashita H. Uchimaru Y. Chem. Commun.  1999,  1763 

7a Jensen JF. Svendsen BY. la Cour TV. Pedersen HL. Johannsen M. J. Am. Chem. Soc.  2002,  124:  4558 

7b Shimada T. Mukaide K. Shinohara A. Han JW. Hayashi T. J. Am. Chem. Soc.  2002,  124:  1584 

7c Han JW. Tokunaga N. Hayashi T. J. Am. Chem. Soc.  2001,  123:  12915 

7d Hayashi T. In Comprehensive Asymmetric Catalysis   Vol. 1:  Jacobsen NE. Pfaltz A. Yamamoto H. Springer; Berlin: 1999.  Chap. 7.

7e Hayashi T. Acta Chem. Scand.  1996,  50:  259 

7f Nishiyama H. Itoh K. In Catalytic Asymmetric Synthesis   2nd ed.:  Ojima I. VCH; New York: 2000.  p.111-143  

8 For the use of electron rich Pd(0)/trialkylphoshine catalysts, see: Netherton MR. Fu GC. Org. Lett.  2001,  3:  4295 ; and ref. 3 therein

9a Lewis LN. Sy KG. Bryant GL. Donahue PE. Organometallics  1991,  10:  3750 

9b Lewis LN. Sy KG. Donahue PE. J. Organomet. Chem.  1992,  427:  165 

9c Chauhan M. Hauck BJ. Keller LP. Boudjouk P. J. Organomet. Chem.  2002,  645:  1 

9d For hydrosilylation with Ph₃SiH under other metal catalyses, see: Bartik T. Nagy G. Kvintovics P. Happ B. J. Organomet. Chem.  1993,  453:  29 

9e Also see: Faller JW. D’Alliessi DP. Organometallics  2002,  21:  1743 

10

Experimental Procedure: The reaction of dodec-1-en-11-yne with Ph₃SiH is representative. In a 30 mL round-bottomed flask, Pd₂(dba)₃·CHCl₃ (5.2 mg, 0.005 mmol) and tricyclohexylphosphine (5.6 mg, 0.02 mmol) were placed under argon atmosphere, and dodec-1-en-11-yne (0.26 mL, 1.2 mmol) was introduced via a syringe. The mixture was stirred well for 10 min to make it homogeneous. To the mixture, triphenylsilane (260 mg, 1.0 mmol) was added at room temperature. Triphenylsilane was soon dissolved and the mixture became homogeneous. After 1 h, the reaction mixture was submitted on silica gel purification to provide (E)-1-triphenylsilyl-dodeca-1,11-diene (369 mg, 0.87 mmol) in 87% yield along with a minor amount of 2-triphenylsilyl-dodeca-1,11-diene (3%).

11

None of alkenylsilanes were obtained with triethylsilane.

12 Kinoshita H. Nakamura T. Kakiya H. Shinokubo H. Matsubara S. Oshima K. Org. Lett.  2001,  3:  2521 

13

Experimental Procedure for Aqueous Reaction: In a round-bottomed flask, Pd₂(dba)₃·CHCl₃ (5.2 mg, 0.005 mmol), tris(2,4,6-trimethoxyphenyl)phosphine (10.7 mg, 0.02 mmol), and 1-octyne (0.30 mL, 2.0 mmol) were mixed well. To the mixture, distilled water (5 mL, non-degassed) was introduced and the mixture was stirred vigorously (1500 rpm) for 5 min. Triphenylsilane (260 mg, 1.0 mmol) was then added, and the heterogeneous mixture was stirred vigorously for 6 h. Extractive workup and purification provided (E)-1-triphenylsilyl-1-octene (256 mg, 0.69 mmol) along with 2-triphenylsilyl-1-octene (13%).

14

An addition of a small amount of water (0.1 mL) to the neat reaction did not enhance the reactivity. Therefore, the amount of water is essential.