plausible. There has been increasing interest and advances in catalyst development
for dehydrogenations of functionalized systems, in particular dehydrogenations of
heterocyclic amines and ethers. Applications to more complex molecules and late
stage functionalizations of pharmaceuticals represent attractive future endeavors in
this area.
This period has also seen numerous advances in coupling transfer dehydrogenation with a second transformation. Increased efficiency in homogeneous alkane
metathesis has been reported, but achieving high selectivity for converting the C n
alkane to ethane and the C 2n-2 alkane has proved elusive. The high temperatures
required for pincer iridium-catalyzed dehydrogenation result in short lifetimes of the
olefin metathesis catalysts, so a challenge to be addressed is to develop a highly
thermally stable olefin metathesis catalyst or a homogeneous dehydrogenation catalyst that functions efficiently at much lower temperatures. Other attractive processes
which likely will see more development include alkyl group cross-metathesis
whereby ethyl benzene plus a linear alkane can be converted to benzene bearing a
linear long-chain alkyl group, alkane–alkene coupling employing tandem iridium and
tantalum catalysts, and combining Diels–Alder reactions of dienes produced through
hydrogen transfer reactions to ultimately lead to valuable aromatics such as p-xylene
and toluene. Coupling other catalytic reactions involving olefins to their generation
via dehydrogenation is also an area ripe for further exploitation.
Acknowledgments We gratefully acknowledge the financial support of the National Science
Foundation as part of the Center for Enabling New Technologies through Catalysis (CENTC),
Phase II Renewal, CHE-1205189.
References
1. Weissermel K, Arpe H-J (2008) Olefins. In: Industrial organic chemistry. Wiley, Weinheim,
pp 59–89
2. Baudry D, Ephritikhine M, Felkin H, Holmes-Smith R (1983) J Chem Soc Chem Commun
788–789
3. Felkin H, Fillebeen-Khan T, Gault Y, Holmes-Smith R, Zakrzewski J (1984) Tetrahedron Lett
25:1279–1282
4. Felkin H, Fillebeen-khan T, Holmes-Smith R, Yingrui L (1985) Tetrahedron Lett
26:1999–2000
5. Burk MJ, Crabtree RH, Parnell CP, Uriarte RJ (1984) Organometallics 3:816–817
6. Burk MJ, Crabtree RH, McGrath DV (1985) J Chem Soc Chem Commun 1829–1830
7. Burk MJ, Crabtree RH (1987) J Am Chem Soc 109:8025–8032
8. Aoki T, Crabtree RH (1993) Organometallics 12:294–298
9. Nomura K, Saito Y (1988) J Chem Soc Chem Commun 161–162
10. Sakakura T, Sodeyama T, Tokunaga Y, Tanaka M (1988) Chem Lett 263–264
11. Maguire JA, Boese WT, Goldman AS (1989) J Am Chem Soc 111:7088–7093
12. Maguire JA, Boese WT, Goldman ME, Goldman AS (1990) Coord Chem Rev 97:179–192
13. Maguire JA, Goldman AS (1991) J Am Chem Soc 113:6706–6708
14. Maguire JA, Petrillo A, Goldman AS (1992) J Am Chem Soc 114:9492–9498
15. Wang K, Goldman ME, Emge TJ, Goldman AS (1996) J Organomet Chem 518:55–68
Transfer Dehydrogenations of Alkanes and Related Reactions Using Iridium. . .
205
for dehydrogenations of functionalized systems, in particular dehydrogenations of
heterocyclic amines and ethers. Applications to more complex molecules and late
stage functionalizations of pharmaceuticals represent attractive future endeavors in
this area.
This period has also seen numerous advances in coupling transfer dehydrogenation with a second transformation. Increased efficiency in homogeneous alkane
metathesis has been reported, but achieving high selectivity for converting the C n
alkane to ethane and the C 2n-2 alkane has proved elusive. The high temperatures
required for pincer iridium-catalyzed dehydrogenation result in short lifetimes of the
olefin metathesis catalysts, so a challenge to be addressed is to develop a highly
thermally stable olefin metathesis catalyst or a homogeneous dehydrogenation catalyst that functions efficiently at much lower temperatures. Other attractive processes
which likely will see more development include alkyl group cross-metathesis
whereby ethyl benzene plus a linear alkane can be converted to benzene bearing a
linear long-chain alkyl group, alkane–alkene coupling employing tandem iridium and
tantalum catalysts, and combining Diels–Alder reactions of dienes produced through
hydrogen transfer reactions to ultimately lead to valuable aromatics such as p-xylene
and toluene. Coupling other catalytic reactions involving olefins to their generation
via dehydrogenation is also an area ripe for further exploitation.
Acknowledgments We gratefully acknowledge the financial support of the National Science
Foundation as part of the Center for Enabling New Technologies through Catalysis (CENTC),
Phase II Renewal, CHE-1205189.
References
1. Weissermel K, Arpe H-J (2008) Olefins. In: Industrial organic chemistry. Wiley, Weinheim,
pp 59–89
2. Baudry D, Ephritikhine M, Felkin H, Holmes-Smith R (1983) J Chem Soc Chem Commun
788–789
3. Felkin H, Fillebeen-Khan T, Gault Y, Holmes-Smith R, Zakrzewski J (1984) Tetrahedron Lett
25:1279–1282
4. Felkin H, Fillebeen-khan T, Holmes-Smith R, Yingrui L (1985) Tetrahedron Lett
26:1999–2000
5. Burk MJ, Crabtree RH, Parnell CP, Uriarte RJ (1984) Organometallics 3:816–817
6. Burk MJ, Crabtree RH, McGrath DV (1985) J Chem Soc Chem Commun 1829–1830
7. Burk MJ, Crabtree RH (1987) J Am Chem Soc 109:8025–8032
8. Aoki T, Crabtree RH (1993) Organometallics 12:294–298
9. Nomura K, Saito Y (1988) J Chem Soc Chem Commun 161–162
10. Sakakura T, Sodeyama T, Tokunaga Y, Tanaka M (1988) Chem Lett 263–264
11. Maguire JA, Boese WT, Goldman AS (1989) J Am Chem Soc 111:7088–7093
12. Maguire JA, Boese WT, Goldman ME, Goldman AS (1990) Coord Chem Rev 97:179–192
13. Maguire JA, Goldman AS (1991) J Am Chem Soc 113:6706–6708
14. Maguire JA, Petrillo A, Goldman AS (1992) J Am Chem Soc 114:9492–9498
15. Wang K, Goldman ME, Emge TJ, Goldman AS (1996) J Organomet Chem 518:55–68
Transfer Dehydrogenations of Alkanes and Related Reactions Using Iridium. . .
205