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Addition of alkynes to aldehydes and activated ketones catalyzed by rhodium-phosphine complexes.
J Org Chem. 2007 Dec 07; 72(25):9590-6.JO

Abstract

A mixture of 2-(di-tert-butylphosphino)biphenyl and dicarbonylacetonato rhodium(I) provides an effective catalyst system for the addition of alkynes to aldehydes and activated ketones. In contrast to the more common zinc-catalyzed processes, enolizable 1,2-dicarbonyls are excellent substrates for these rhodium-catalyzed additions. This reaction allows for the formation of propargylic alcohols under mild conditions, tolerating many functional groups (such as carboxylic acids) that are incompatible with other methods. Little selectivity was observed in cases of unsymmetrical 1,2-diketones. Addition of alkynes to aldehydes with an adjacent chirality center usually provides the Felkin addition product with excellent selectivity in some cases. Studies on the catalyst structure show that both the beta-diketonate and a carbon monoxide ligand appear to be bound to the active catalyst. The use of chiral phosphines to induce asymmetry in the propargyl alcohol products provided low enantioselectivity, which may be due to the phosphine having a distal relationship to the reacting centers. Modification of other ligands, such as the beta-diketonate, appears to be a more promising avenue for the development of an enantioselective variant.

Authors+Show Affiliations

Department of Chemistry, 1-014 Center for Science and Technology, Syracuse University, Syracuse, New York 13244, USA.No affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

17999525

Citation

Dhondi, Pawan K., et al. "Addition of Alkynes to Aldehydes and Activated Ketones Catalyzed By Rhodium-phosphine Complexes." The Journal of Organic Chemistry, vol. 72, no. 25, 2007, pp. 9590-6.
Dhondi PK, Carberry P, Choi LB, et al. Addition of alkynes to aldehydes and activated ketones catalyzed by rhodium-phosphine complexes. J Org Chem. 2007;72(25):9590-6.
Dhondi, P. K., Carberry, P., Choi, L. B., & Chisholm, J. D. (2007). Addition of alkynes to aldehydes and activated ketones catalyzed by rhodium-phosphine complexes. The Journal of Organic Chemistry, 72(25), 9590-6.
Dhondi PK, et al. Addition of Alkynes to Aldehydes and Activated Ketones Catalyzed By Rhodium-phosphine Complexes. J Org Chem. 2007 Dec 7;72(25):9590-6. PubMed PMID: 17999525.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Addition of alkynes to aldehydes and activated ketones catalyzed by rhodium-phosphine complexes. AU - Dhondi,Pawan K, AU - Carberry,Patrick, AU - Choi,Lydia B, AU - Chisholm,John D, Y1 - 2007/11/14/ PY - 2007/11/15/pubmed PY - 2008/2/21/medline PY - 2007/11/15/entrez SP - 9590 EP - 6 JF - The Journal of organic chemistry JO - J Org Chem VL - 72 IS - 25 N2 - A mixture of 2-(di-tert-butylphosphino)biphenyl and dicarbonylacetonato rhodium(I) provides an effective catalyst system for the addition of alkynes to aldehydes and activated ketones. In contrast to the more common zinc-catalyzed processes, enolizable 1,2-dicarbonyls are excellent substrates for these rhodium-catalyzed additions. This reaction allows for the formation of propargylic alcohols under mild conditions, tolerating many functional groups (such as carboxylic acids) that are incompatible with other methods. Little selectivity was observed in cases of unsymmetrical 1,2-diketones. Addition of alkynes to aldehydes with an adjacent chirality center usually provides the Felkin addition product with excellent selectivity in some cases. Studies on the catalyst structure show that both the beta-diketonate and a carbon monoxide ligand appear to be bound to the active catalyst. The use of chiral phosphines to induce asymmetry in the propargyl alcohol products provided low enantioselectivity, which may be due to the phosphine having a distal relationship to the reacting centers. Modification of other ligands, such as the beta-diketonate, appears to be a more promising avenue for the development of an enantioselective variant. SN - 0022-3263 UR - https://www.unboundmedicine.com/medline/citation/17999525/Addition_of_alkynes_to_aldehydes_and_activated_ketones_catalyzed_by_rhodium_phosphine_complexes_ L2 - https://doi.org/10.1021/jo701643h DB - PRIME DP - Unbound Medicine ER -