C-H Activation and Palladium Migration within Biaryls under Heck Reaction Conditions

Organic Letters

Volumn 4, Issue 18, 2002, Pages 3115-3118

  Karig, Gunter ^a   Moon, Maria Teresa ^a   Thasana, Nopporn ^a,b,c   Gallagher, Timothy ^a  

^a UNIVERSITY OF BRISTOL   (United Kingdom)

^b CHULABHORN RESEARCH INSTITUTE   (Thailand)

^c MAHIDOL UNIVERSITY   (Thailand)

Author keywords

[No Author keywords available]

Indexed keywords

ARTICLE;

EID: 0001651123     PISSN: 15237060     EISSN: None     Source Type: Journal    
DOI: 10.1021/ol026426v     Document Type: Article

References (43)

1. Karig, G.; Spencer, J. A.; Gallagher, T. Org. Lett. 2001, 3, 835-838. Karig, G.; Thasana, N.; Gallagher, T. Synlett 2002, 808-810.
2. Karig, G.; Spencer, J. A.; Gallagher, T. Org. Lett. 2001, 3, 835-838. Karig, G.; Thasana, N.; Gallagher, T. Synlett 2002, 808-810.
3. Heck, R. F.; Nolley, J. P. J. Org. Chem. 1972, 37, 2320-2322. Mizoroki, T.; Mori, K.; Ozaki, A. Bull. Chem. Soc. Jpn. 1971, 44, 581.
4. Heck, R. F.; Nolley, J. P. J. Org. Chem. 1972, 37, 2320-2322. Mizoroki, T.; Mori, K.; Ozaki, A. Bull. Chem. Soc. Jpn. 1971, 44, 581.
5. For overviews of the Heck reaction, see: de Meijere, A.; Meyer, F. E. Angew. Chem., Int. Ed. Engl. 1994, 33, 2379-2411. Bräse, S.; de Meijere, A. In Metal-Catalyzed Cross-Coupling Reactions; Diederich, F., Stang, P. J., Eds.; Wiley-VCH: New York, 1998; pp 99-166. Beletskaya, I. P.; Cheprakov, A. V. Chem. Rev. 2000, 100, 3009-3066. For recent mechanistic work, including a role for Pd(IV) intermediates, see: Crisp, G. T. Chem. Soc. Rev. 1998, 27, 427-436. Shaw, B. L. New J. Chem. 1998, 22, 77-79. Shaw, B. L.; Perera, S. D.; Staley, E. A. Chem. Commun. 1998, 1361-1362. Amatore, C.; Jutand, A. J. Organomet. Chem. 1999, 576, 254-278. Amatore, C.; Jutand, A. Acc. Chem. Res. 2000, 33, 314-321. Böhm, V. P. W.; Herrmann, W. A. Chem. Eur. J. 2001, 7, 4191-4197. Sundermann, A.; Uzan, O.; Martin, J. M. L. Chem. Eur. J. 2001, 7, 1703-1711.
6. For overviews of the Heck reaction, see: de Meijere, A.; Meyer, F. E. Angew. Chem., Int. Ed. Engl. 1994, 33, 2379-2411. Bräse, S.; de Meijere, A. In Metal-Catalyzed Cross-Coupling Reactions; Diederich, F., Stang, P. J., Eds.; Wiley-VCH: New York, 1998; pp 99-166. Beletskaya, I. P.; Cheprakov, A. V. Chem. Rev. 2000, 100, 3009-3066. For recent mechanistic work, including a role for Pd(IV) intermediates, see: Crisp, G. T. Chem. Soc. Rev. 1998, 27, 427-436. Shaw, B. L. New J. Chem. 1998, 22, 77-79. Shaw, B. L.; Perera, S. D.; Staley, E. A. Chem. Commun. 1998, 1361-1362. Amatore, C.; Jutand, A. J. Organomet. Chem. 1999, 576, 254-278. Amatore, C.; Jutand, A. Acc. Chem. Res. 2000, 33, 314-321. Böhm, V. P. W.; Herrmann, W. A. Chem. Eur. J. 2001, 7, 4191-4197. Sundermann, A.; Uzan, O.; Martin, J. M. L. Chem. Eur. J. 2001, 7, 1703-1711.
7. For overviews of the Heck reaction, see: de Meijere, A.; Meyer, F. E. Angew. Chem., Int. Ed. Engl. 1994, 33, 2379-2411. Bräse, S.; de Meijere, A. In Metal-Catalyzed Cross-Coupling Reactions; Diederich, F., Stang, P. J., Eds.; Wiley-VCH: New York, 1998; pp 99-166. Beletskaya, I. P.; Cheprakov, A. V. Chem. Rev. 2000, 100, 3009-3066. For recent mechanistic work, including a role for Pd(IV) intermediates, see: Crisp, G. T. Chem. Soc. Rev. 1998, 27, 427-436. Shaw, B. L. New J. Chem. 1998, 22, 77-79. Shaw, B. L.; Perera, S. D.; Staley, E. A. Chem. Commun. 1998, 1361-1362. Amatore, C.; Jutand, A. J. Organomet. Chem. 1999, 576, 254-278. Amatore, C.; Jutand, A. Acc. Chem. Res. 2000, 33, 314-321. Böhm, V. P. W.; Herrmann, W. A. Chem. Eur. J. 2001, 7, 4191-4197. Sundermann, A.; Uzan, O.; Martin, J. M. L. Chem. Eur. J. 2001, 7, 1703-1711.
8. For overviews of the Heck reaction, see: de Meijere, A.; Meyer, F. E. Angew. Chem., Int. Ed. Engl. 1994, 33, 2379-2411. Bräse, S.; de Meijere, A. In Metal-Catalyzed Cross-Coupling Reactions; Diederich, F., Stang, P. J., Eds.; Wiley-VCH: New York, 1998; pp 99-166. Beletskaya, I. P.; Cheprakov, A. V. Chem. Rev. 2000, 100, 3009-3066. For recent mechanistic work, including a role for Pd(IV) intermediates, see: Crisp, G. T. Chem. Soc. Rev. 1998, 27, 427-436. Shaw, B. L. New J. Chem. 1998, 22, 77-79. Shaw, B. L.; Perera, S. D.; Staley, E. A. Chem. Commun. 1998, 1361-1362. Amatore, C.; Jutand, A. J. Organomet. Chem. 1999, 576, 254-278. Amatore, C.; Jutand, A. Acc. Chem. Res. 2000, 33, 314-321. Böhm, V. P. W.; Herrmann, W. A. Chem. Eur. J. 2001, 7, 4191-4197. Sundermann, A.; Uzan, O.; Martin, J. M. L. Chem. Eur. J. 2001, 7, 1703-1711.
9. For overviews of the Heck reaction, see: de Meijere, A.; Meyer, F. E. Angew. Chem., Int. Ed. Engl. 1994, 33, 2379-2411. Bräse, S.; de Meijere, A. In Metal-Catalyzed Cross-Coupling Reactions; Diederich, F., Stang, P. J., Eds.; Wiley-VCH: New York, 1998; pp 99-166. Beletskaya, I. P.; Cheprakov, A. V. Chem. Rev. 2000, 100, 3009-3066. For recent mechanistic work, including a role for Pd(IV) intermediates, see: Crisp, G. T. Chem. Soc. Rev. 1998, 27, 427-436. Shaw, B. L. New J. Chem. 1998, 22, 77-79. Shaw, B. L.; Perera, S. D.; Staley, E. A. Chem. Commun. 1998, 1361-1362. Amatore, C.; Jutand, A. J. Organomet. Chem. 1999, 576, 254-278. Amatore, C.; Jutand, A. Acc. Chem. Res. 2000, 33, 314-321. Böhm, V. P. W.; Herrmann, W. A. Chem. Eur. J. 2001, 7, 4191-4197. Sundermann, A.; Uzan, O.; Martin, J. M. L. Chem. Eur. J. 2001, 7, 1703-1711.
10. For overviews of the Heck reaction, see: de Meijere, A.; Meyer, F. E. Angew. Chem., Int. Ed. Engl. 1994, 33, 2379-2411. Bräse, S.; de Meijere, A. In Metal-Catalyzed Cross-Coupling Reactions; Diederich, F., Stang, P. J., Eds.; Wiley-VCH: New York, 1998; pp 99-166. Beletskaya, I. P.; Cheprakov, A. V. Chem. Rev. 2000, 100, 3009-3066. For recent mechanistic work, including a role for Pd(IV) intermediates, see: Crisp, G. T. Chem. Soc. Rev. 1998, 27, 427-436. Shaw, B. L. New J. Chem. 1998, 22, 77-79. Shaw, B. L.; Perera, S. D.; Staley, E. A. Chem. Commun. 1998, 1361-1362. Amatore, C.; Jutand, A. J. Organomet. Chem. 1999, 576, 254-278. Amatore, C.; Jutand, A. Acc. Chem. Res. 2000, 33, 314-321. Böhm, V. P. W.; Herrmann, W. A. Chem. Eur. J. 2001, 7, 4191-4197. Sundermann, A.; Uzan, O.; Martin, J. M. L. Chem. Eur. J. 2001, 7, 1703-1711.
11. For overviews of the Heck reaction, see: de Meijere, A.; Meyer, F. E. Angew. Chem., Int. Ed. Engl. 1994, 33, 2379-2411. Bräse, S.; de Meijere, A. In Metal-Catalyzed Cross-Coupling Reactions; Diederich, F., Stang, P. J., Eds.; Wiley-VCH: New York, 1998; pp 99-166. Beletskaya, I. P.; Cheprakov, A. V. Chem. Rev. 2000, 100, 3009-3066. For recent mechanistic work, including a role for Pd(IV) intermediates, see: Crisp, G. T. Chem. Soc. Rev. 1998, 27, 427-436. Shaw, B. L. New J. Chem. 1998, 22, 77-79. Shaw, B. L.; Perera, S. D.; Staley, E. A. Chem. Commun. 1998, 1361-1362. Amatore, C.; Jutand, A. J. Organomet. Chem. 1999, 576, 254-278. Amatore, C.; Jutand, A. Acc. Chem. Res. 2000, 33, 314-321. Böhm, V. P. W.; Herrmann, W. A. Chem. Eur. J. 2001, 7, 4191-4197. Sundermann, A.; Uzan, O.; Martin, J. M. L. Chem. Eur. J. 2001, 7, 1703-1711.
12. For overviews of the Heck reaction, see: de Meijere, A.; Meyer, F. E. Angew. Chem., Int. Ed. Engl. 1994, 33, 2379-2411. Bräse, S.; de Meijere, A. In Metal-Catalyzed Cross-Coupling Reactions; Diederich, F., Stang, P. J., Eds.; Wiley-VCH: New York, 1998; pp 99-166. Beletskaya, I. P.; Cheprakov, A. V. Chem. Rev. 2000, 100, 3009-3066. For recent mechanistic work, including a role for Pd(IV) intermediates, see: Crisp, G. T. Chem. Soc. Rev. 1998, 27, 427-436. Shaw, B. L. New J. Chem. 1998, 22, 77-79. Shaw, B. L.; Perera, S. D.; Staley, E. A. Chem. Commun. 1998, 1361-1362. Amatore, C.; Jutand, A. J. Organomet. Chem. 1999, 576, 254-278. Amatore, C.; Jutand, A. Acc. Chem. Res. 2000, 33, 314-321. Böhm, V. P. W.; Herrmann, W. A. Chem. Eur. J. 2001, 7, 4191-4197. Sundermann, A.; Uzan, O.; Martin, J. M. L. Chem. Eur. J. 2001, 7, 1703-1711.
13. For overviews of the Heck reaction, see: de Meijere, A.; Meyer, F. E. Angew. Chem., Int. Ed. Engl. 1994, 33, 2379-2411. Bräse, S.; de Meijere, A. In Metal-Catalyzed Cross-Coupling Reactions; Diederich, F., Stang, P. J., Eds.; Wiley-VCH: New York, 1998; pp 99-166. Beletskaya, I. P.; Cheprakov, A. V. Chem. Rev. 2000, 100, 3009-3066. For recent mechanistic work, including a role for Pd(IV) intermediates, see: Crisp, G. T. Chem. Soc. Rev. 1998, 27, 427-436. Shaw, B. L. New J. Chem. 1998, 22, 77-79. Shaw, B. L.; Perera, S. D.; Staley, E. A. Chem. Commun. 1998, 1361-1362. Amatore, C.; Jutand, A. J. Organomet. Chem. 1999, 576, 254-278. Amatore, C.; Jutand, A. Acc. Chem. Res. 2000, 33, 314-321. Böhm, V. P. W.; Herrmann, W. A. Chem. Eur. J. 2001, 7, 4191-4197. Sundermann, A.; Uzan, O.; Martin, J. M. L. Chem. Eur. J. 2001, 7, 1703-1711.
14. For overviews of the Heck reaction, see: de Meijere, A.; Meyer, F. E. Angew. Chem., Int. Ed. Engl. 1994, 33, 2379-2411. Bräse, S.; de Meijere, A. In Metal-Catalyzed Cross-Coupling Reactions; Diederich, F., Stang, P. J., Eds.; Wiley-VCH: New York, 1998; pp 99-166. Beletskaya, I. P.; Cheprakov, A. V. Chem. Rev. 2000, 100, 3009-3066. For recent mechanistic work, including a role for Pd(IV) intermediates, see: Crisp, G. T. Chem. Soc. Rev. 1998, 27, 427-436. Shaw, B. L. New J. Chem. 1998, 22, 77-79. Shaw, B. L.; Perera, S. D.; Staley, E. A. Chem. Commun. 1998, 1361-1362. Amatore, C.; Jutand, A. J. Organomet. Chem. 1999, 576, 254-278. Amatore, C.; Jutand, A. Acc. Chem. Res. 2000, 33, 314-321. Böhm, V. P. W.; Herrmann, W. A. Chem. Eur. J. 2001, 7, 4191-4197. Sundermann, A.; Uzan, O.; Martin, J. M. L. Chem. Eur. J. 2001, 7, 1703-1711.
15. 1 The preparation of biaryls 12a-d was carried out using an aryl boronic acid and an appropriately substituted 2-iodo-1-bromoarene. Experimental details are available in Supporting Information.
16. 2 under our conditions gave no crossover product.
17. Ryabov, A. D. Chem. Rev. 1990, 90, 403-424. Dyker, G. Chem. Ber. 1997, 130, 1567-1578. Dyker, G. Angew. Chem., Int. Ed. 1999, 38, 1699-1712. Jia, C. G.; Kitamura, T.; Fujiwara, Y. Acc. Chem. Res. 2001, 34, 633-639. For insertion into aryl C-H via electrophilic substitution, see: Markies, B. A.; Wijkens, P.; Kooijman, H.; Spek, A. L.; Boersma, J.; van Koten G. J. Chem. Soc., Chem. Commun. 1992, 1420-1423. For the effect of substituents on the rate of C-H, see: Catellani, M.; Chiusoli, G. P. J. Organomet. Chem. 1992, 425, 151-154.
18. Ryabov, A. D. Chem. Rev. 1990, 90, 403-424. Dyker, G. Chem. Ber. 1997, 130, 1567-1578. Dyker, G. Angew. Chem., Int. Ed. 1999, 38, 1699-1712. Jia, C. G.; Kitamura, T.; Fujiwara, Y. Acc. Chem. Res. 2001, 34, 633-639. For insertion into aryl C-H via electrophilic substitution, see: Markies, B. A.; Wijkens, P.; Kooijman, H.; Spek, A. L.; Boersma, J.; van Koten G. J. Chem. Soc., Chem. Commun. 1992, 1420-1423. For the effect of substituents on the rate of C-H, see: Catellani, M.; Chiusoli, G. P. J. Organomet. Chem. 1992, 425, 151-154.
19. Ryabov, A. D. Chem. Rev. 1990, 90, 403-424. Dyker, G. Chem. Ber. 1997, 130, 1567-1578. Dyker, G. Angew. Chem., Int. Ed. 1999, 38, 1699-1712. Jia, C. G.; Kitamura, T.; Fujiwara, Y. Acc. Chem. Res. 2001, 34, 633-639. For insertion into aryl C-H via electrophilic substitution, see: Markies, B. A.; Wijkens, P.; Kooijman, H.; Spek, A. L.; Boersma, J.; van Koten G. J. Chem. Soc., Chem. Commun. 1992, 1420-1423. For the effect of substituents on the rate of C-H, see: Catellani, M.; Chiusoli, G. P. J. Organomet. Chem. 1992, 425, 151-154.
20. Ryabov, A. D. Chem. Rev. 1990, 90, 403-424. Dyker, G. Chem. Ber. 1997, 130, 1567-1578. Dyker, G. Angew. Chem., Int. Ed. 1999, 38, 1699-1712. Jia, C. G.; Kitamura, T.; Fujiwara, Y. Acc. Chem. Res. 2001, 34, 633-639. For insertion into aryl C-H via electrophilic substitution, see: Markies, B. A.; Wijkens, P.; Kooijman, H.; Spek, A. L.; Boersma, J.; van Koten G. J. Chem. Soc., Chem. Commun. 1992, 1420-1423. For the effect of substituents on the rate of C-H, see: Catellani, M.; Chiusoli, G. P. J. Organomet. Chem. 1992, 425, 151-154.
21. Ryabov, A. D. Chem. Rev. 1990, 90, 403-424. Dyker, G. Chem. Ber. 1997, 130, 1567-1578. Dyker, G. Angew. Chem., Int. Ed. 1999, 38, 1699-1712. Jia, C. G.; Kitamura, T.; Fujiwara, Y. Acc. Chem. Res. 2001, 34, 633-639. For insertion into aryl C-H via electrophilic substitution, see: Markies, B. A.; Wijkens, P.; Kooijman, H.; Spek, A. L.; Boersma, J.; van Koten G. J. Chem. Soc., Chem. Commun. 1992, 1420-1423. For the effect of substituents on the rate of C-H, see: Catellani, M.; Chiusoli, G. P. J. Organomet. Chem. 1992, 425, 151-154.
22. Ryabov, A. D. Chem. Rev. 1990, 90, 403-424. Dyker, G. Chem. Ber. 1997, 130, 1567-1578. Dyker, G. Angew. Chem., Int. Ed. 1999, 38, 1699-1712. Jia, C. G.; Kitamura, T.; Fujiwara, Y. Acc. Chem. Res. 2001, 34, 633-639. For insertion into aryl C-H via electrophilic substitution, see: Markies, B. A.; Wijkens, P.; Kooijman, H.; Spek, A. L.; Boersma, J.; van Koten G. J. Chem. Soc., Chem. Commun. 1992, 1420-1423. For the effect of substituents on the rate of C-H, see: Catellani, M.; Chiusoli, G. P. J. Organomet. Chem. 1992, 425, 151-154.
23. de Meijere, A.; Bräse, S. J. Organomet. Chem. 1999, 576, 88-110. Larock, R. C. J. Organomet. Chem. 1999, 576, 111-124. Cámpora, J.; López, J. A.; Palma, P.; Valerga, P.; Spillner, E.; Carmona, E. Angew. Chem., Int. Ed. 1999, 38, 147-151. Catellani, M.; Motti, E.; Paterlini, L.; Bocelli, G.; Righi, L. J. Organomet. Chem. 1999, 580, 191-196. Catellani, M.; Motti, E.; Paterlini, L. J. Organomet. Chem. 2000, 594, 240-244. Catellani, M.; Motti, E.; Baratta, S. Org. Lett. 2001, 3, 3611-3614. C-H Activation via ortho-palladation has been used to mediate the Heck reaction: Boele, M. D. K.; van Strijdonck, G. P. F.; de Vries, A. H. M.; Kamer, P. C. J.; de Vries, J. G.; van Leeuwen, P. W. N. M. J. Am. Chem. Soc. 2002, 124, 1586-1587.
24. de Meijere, A.; Bräse, S. J. Organomet. Chem. 1999, 576, 88-110. Larock, R. C. J. Organomet. Chem. 1999, 576, 111-124. Cámpora, J.; López, J. A.; Palma, P.; Valerga, P.; Spillner, E.; Carmona, E. Angew. Chem., Int. Ed. 1999, 38, 147-151. Catellani, M.; Motti, E.; Paterlini, L.; Bocelli, G.; Righi, L. J. Organomet. Chem. 1999, 580, 191-196. Catellani, M.; Motti, E.; Paterlini, L. J. Organomet. Chem. 2000, 594, 240-244. Catellani, M.; Motti, E.; Baratta, S. Org. Lett. 2001, 3, 3611-3614. C-H Activation via ortho-palladation has been used to mediate the Heck reaction: Boele, M. D. K.; van Strijdonck, G. P. F.; de Vries, A. H. M.; Kamer, P. C. J.; de Vries, J. G.; van Leeuwen, P. W. N. M. J. Am. Chem. Soc. 2002, 124, 1586-1587.
25. de Meijere, A.; Bräse, S. J. Organomet. Chem. 1999, 576, 88-110. Larock, R. C. J. Organomet. Chem. 1999, 576, 111-124. Cámpora, J.; López, J. A.; Palma, P.; Valerga, P.; Spillner, E.; Carmona, E. Angew. Chem., Int. Ed. 1999, 38, 147-151. Catellani, M.; Motti, E.; Paterlini, L.; Bocelli, G.; Righi, L. J. Organomet. Chem. 1999, 580, 191-196. Catellani, M.; Motti, E.; Paterlini, L. J. Organomet. Chem. 2000, 594, 240-244. Catellani, M.; Motti, E.; Baratta, S. Org. Lett. 2001, 3, 3611-3614. C-H Activation via ortho-palladation has been used to mediate the Heck reaction: Boele, M. D. K.; van Strijdonck, G. P. F.; de Vries, A. H. M.; Kamer, P. C. J.; de Vries, J. G.; van Leeuwen, P. W. N. M. J. Am. Chem. Soc. 2002, 124, 1586-1587.
26. de Meijere, A.; Bräse, S. J. Organomet. Chem. 1999, 576, 88-110. Larock, R. C. J. Organomet. Chem. 1999, 576, 111-124. Cámpora, J.; López, J. A.; Palma, P.; Valerga, P.; Spillner, E.; Carmona, E. Angew. Chem., Int. Ed. 1999, 38, 147-151. Catellani, M.; Motti, E.; Paterlini, L.; Bocelli, G.; Righi, L. J. Organomet. Chem. 1999, 580, 191-196. Catellani, M.; Motti, E.; Paterlini, L. J. Organomet. Chem. 2000, 594, 240-244. Catellani, M.; Motti, E.; Baratta, S. Org. Lett. 2001, 3, 3611-3614. C-H Activation via ortho-palladation has been used to mediate the Heck reaction: Boele, M. D. K.; van Strijdonck, G. P. F.; de Vries, A. H. M.; Kamer, P. C. J.; de Vries, J. G.; van Leeuwen, P. W. N. M. J. Am. Chem. Soc. 2002, 124, 1586-1587.
27. de Meijere, A.; Bräse, S. J. Organomet. Chem. 1999, 576, 88-110. Larock, R. C. J. Organomet. Chem. 1999, 576, 111-124. Cámpora, J.; López, J. A.; Palma, P.; Valerga, P.; Spillner, E.; Carmona, E. Angew. Chem., Int. Ed. 1999, 38, 147-151. Catellani, M.; Motti, E.; Paterlini, L.; Bocelli, G.; Righi, L. J. Organomet. Chem. 1999, 580, 191-196. Catellani, M.; Motti, E.; Paterlini, L. J. Organomet. Chem. 2000, 594, 240-244. Catellani, M.; Motti, E.; Baratta, S. Org. Lett. 2001, 3, 3611-3614. C-H Activation via ortho-palladation has been used to mediate the Heck reaction: Boele, M. D. K.; van Strijdonck, G. P. F.; de Vries, A. H. M.; Kamer, P. C. J.; de Vries, J. G.; van Leeuwen, P. W. N. M. J. Am. Chem. Soc. 2002, 124, 1586-1587.
28. de Meijere, A.; Bräse, S. J. Organomet. Chem. 1999, 576, 88-110. Larock, R. C. J. Organomet. Chem. 1999, 576, 111-124. Cámpora, J.; López, J. A.; Palma, P.; Valerga, P.; Spillner, E.; Carmona, E. Angew. Chem., Int. Ed. 1999, 38, 147-151. Catellani, M.; Motti, E.; Paterlini, L.; Bocelli, G.; Righi, L. J. Organomet. Chem. 1999, 580, 191-196. Catellani, M.; Motti, E.; Paterlini, L. J. Organomet. Chem. 2000, 594, 240-244. Catellani, M.; Motti, E.; Baratta, S. Org. Lett. 2001, 3, 3611-3614. C-H Activation via ortho-palladation has been used to mediate the Heck reaction: Boele, M. D. K.; van Strijdonck, G. P. F.; de Vries, A. H. M.; Kamer, P. C. J.; de Vries, J. G.; van Leeuwen, P. W. N. M. J. Am. Chem. Soc. 2002, 124, 1586-1587.
29. de Meijere, A.; Bräse, S. J. Organomet. Chem. 1999, 576, 88-110. Larock, R. C. J. Organomet. Chem. 1999, 576, 111-124. Cámpora, J.; López, J. A.; Palma, P.; Valerga, P.; Spillner, E.; Carmona, E. Angew. Chem., Int. Ed. 1999, 38, 147-151. Catellani, M.; Motti, E.; Paterlini, L.; Bocelli, G.; Righi, L. J. Organomet. Chem. 1999, 580, 191-196. Catellani, M.; Motti, E.; Paterlini, L. J. Organomet. Chem. 2000, 594, 240-244. Catellani, M.; Motti, E.; Baratta, S. Org. Lett. 2001, 3, 3611-3614. C-H Activation via ortho-palladation has been used to mediate the Heck reaction: Boele, M. D. K.; van Strijdonck, G. P. F.; de Vries, A. H. M.; Kamer, P. C. J.; de Vries, J. G.; van Leeuwen, P. W. N. M. J. Am. Chem. Soc. 2002, 124, 1586-1587.
30. Intervention of the crossover pathway is not simply a function of the alkene component, and reaction of 1a with styrene led to the corresponding retention and crossover products in a 3:1 ratio.
31. 10 The formation of the 2-alkyl, as opposed to 2-alkenyl adducts, may results from direct protonation of the initial carbopalladation product (which is a Pd enolate) that may, in turn, be stabilized by the adjacent pyridyl nitrogen lone pair. We have also observed this pathway for Heck reactions of other 3-aryl-2-bromopyridines with ethyl acrylate (ref 1 and Moon, M.-T., unpublished results). These Heck processes are also inefficient with significant amounts of both starting material and the product of simple C-Br reduction being observed.
32. Bozell, J. J.; Vogt, C. E.; Gozum, J. J. Org. Chem. 1991, 56, 2584-2587. Basu, B.; Frejd, T. Acta Chem. Scand. 1996, 50, 316-322.
33. Bozell, J. J.; Vogt, C. E.; Gozum, J. J. Org. Chem. 1991, 56, 2584-2587. Basu, B.; Frejd, T. Acta Chem. Scand. 1996, 50, 316-322.
34. The formation of aryl halides via reductive elimination from Pd(II) has been reported recently: Roy, A. H.; Hartwig, J. F. J. Am. Chem. Soc. 2001, 123, 1232-1233. The possibility of a Pd-mediated aryl halide exchange occurring between, e.g., 1 and 18, though not detected, cannot be discounted at this time, and the lack of strongly donating ligands may argue against this.
35. Jones has shown that palladacycles corresponding to 16, which are generated by oxidative addition to biphenylene, do undergo Heck and other Pd-mediated reactions. These processes are best performed in the presence of a weak acid, such as p-cresol, to achieve protonolysis of the palladacycle to give species analogous to 15 and 17. Satoh, T.; Jones, W. D. Organometallics 2001, 20, 2916-2919. Edelbach, B. L.; Lachicotte, R. J.; Jones, W. D. J. Am. Chem. Soc. 1998, 120, 2843-2853. See also: Catellani, M.; Cugini, F.; Bocelli, G. J. Organomet. Chem. 1999, 584, 63-67.
36. Jones has shown that palladacycles corresponding to 16, which are generated by oxidative addition to biphenylene, do undergo Heck and other Pd-mediated reactions. These processes are best performed in the presence of a weak acid, such as p-cresol, to achieve protonolysis of the palladacycle to give species analogous to 15 and 17. Satoh, T.; Jones, W. D. Organometallics 2001, 20, 2916-2919. Edelbach, B. L.; Lachicotte, R. J.; Jones, W. D. J. Am. Chem. Soc. 1998, 120, 2843-2853. See also: Catellani, M.; Cugini, F.; Bocelli, G. J. Organomet. Chem. 1999, 584, 63-67.
37. Jones has shown that palladacycles corresponding to 16, which are generated by oxidative addition to biphenylene, do undergo Heck and other Pd-mediated reactions. These processes are best performed in the presence of a weak acid, such as p-cresol, to achieve protonolysis of the palladacycle to give species analogous to 15 and 17. Satoh, T.; Jones, W. D. Organometallics 2001, 20, 2916-2919. Edelbach, B. L.; Lachicotte, R. J.; Jones, W. D. J. Am. Chem. Soc. 1998, 120, 2843-2853. See also: Catellani, M.; Cugini, F.; Bocelli, G. J. Organomet. Chem. 1999, 584, 63-67.
38. González, J. J.; García, N.; Gómez-Lor, B.; Echavarren, A. M. J. Org. Chem. 1997, 62, 1286-1291. See also: Martín-Matute, B.; Mateo, C.; Cárdenas, D. J.; Echavarren, A. M. Chem. Eur. J. 2001, 7, 2341-2348
39. González, J. J.; García, N.; Gómez-Lor, B.; Echavarren, A. M. J. Org. Chem. 1997, 62, 1286-1291. See also: Martín-Matute, B.; Mateo, C.; Cárdenas, D. J.; Echavarren, A. M. Chem. Eur. J. 2001, 7, 2341-2348
40. 6,13 and this is more consistent with our observations.
41. 16 where Pd insertion into both H(2) and H(4) of a pyridine nucleus is observed, but in this case H(4) insertion is preferred.
42. Larock, R. C.; Tian, Q. P. J. Org. Chem. 2001, 66, 7372-7379.
43. Larock, R. C.; Campo, M. A. Submitted for publication. These authors observe different trends to those described here, and it is important to appreciate that other conditions for the Heck reaction have been used. The significance of these experimental factors will hopefully emerge in the future.