Enhancing regiocontrol in carboaluminations of terminal alkynes. Application to the one-pot synthesis of coenzyme Q10.
Two new "generations" of methodological advances are reported for the Negishi carboalumination of terminal alkynes. Use of simple, inexpensive additives that alter the Al-Zr complex formed between Me(3)Al and Cp(2)ZrCl(2) give rise to an especially effective reagent mix that results in virtually complete control of regiochemistry upon carboalumination of 1-alkynes. One timely application to coenzyme Q10 is highlighted. Regioisomers from subsequent coupling, which would otherwise be very difficult to separate, are avoided.
Lipshutz
Bruce H
BH
Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, USA. lipshutz@chem.ucsb.edu
Butler
Tom
T
Lower
Asher
A
Servesko
Jeff
J
D000480:Alkynes / Q000737:chemistry*; D000535:Aluminum / Q000737:chemistry*; D002384:Catalysis; D003067:Coenzymes / Q000138:chemical synthesis / Q000737:chemistry; D049449:Luminescence; D015394:Molecular Structure; D017640:Silicates / Q000737:chemistry; D014451:Ubiquinone / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D015040:Zirconium / Q000737:chemistry
D000480:Alkynes; D003067:Coenzymes; D017640:Silicates; D014451:Ubiquinone; C003784:zircon; D015040:Zirconium; D000535:Aluminum; C024989:coenzyme Q10