Zoltan Hajos

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Zoltan Hajos
Born (1926-03-03) 3 March 1926 (age 98)
Budapest, Hungary
Nationality Hungarian-American[citation needed]
Fields Organic chemistry
Institutions Hoffmann-La Roche, Johnson & Johnson
Alma mater Technical University of Budapest
Doctoral advisor Zoltan Csuros
Known for Organocatalysis, total synthesis of steroids

Zoltan Hajos (born 3 March 1926) is a Hungarian-born and trained American organic chemist. Originally an academic in his native Budapest, then an industrial chemist in the pharmaceutical industry, he is known for the Hajos–Parrish–Eder–Sauer–Wiechert reaction (originally named Hajos-Parrish reaction by Claude Agami[1] in 1985).

Biography

Chemistry training

Hajos studied chemistry at the Technical University of Budapest (TU Budapest), in Hungary, completing an M.Sc. in 1947,[2] and his doctoral work under Zoltan Csuros of the Institute of Organic Chemical Technology in 1950.[2]

Early academic career

Hajos remained there until accepting a position as assistant professor in organic chemistry at the TU Budapest in 1948, where he stayed until 1952,[citation needed] then as Lecturer at the University of Veszprem (1952-1953),[citation needed] returning as a Research Associate at the Institute of Organic Chemistry at TU Budapest in 1953.[citation needed] With backlash following the 1956 Revolution in October, 1956,[3] Hajos left TU Budapest and communist Hungary for the United States, where he took a position as a research associate in organic chemistry, a senior postdoctoral-level position, in the Department of Chemistry at Princeton University, beginning in 1957.[citation needed]

Second academic and pharmaceutical periods

Hajos accepted a chemistry position with the Pharmaceutical Research Institute of Hoffmann-La Roche, a pharmaceutical company, in Nutley, New Jersey, in 1960.[citation needed] He remained in that position until beginning a second phase of an academic career in 1970, first in the Chemistry Department of the University of Vermont (1972-1973), and thereafter on the Faculty of Pharmacy of the University of Toronto (1973 -1974).[citation needed] Hajos returned to the pharmaceutical industry in 1975, proceeding through a series of positions at the Research Institute of Johnson & Johnson, until retiring in 1990.[citation needed]

Research

Hajos–Parrish–Eder–Sauer–Wiechert reaction, discovery and importance

File:Hajos-Parrish Patent Application 2102623.png
Front page of the German Patent Application no. 21 02 623, published July 29, 1971

Hajos is noted for the Hajos–Parrish–Eder–Sauer–Wiechert reaction,[4] and of the related (S)-proline-catalyzed synthesis route to the Hajos-Wiechert ketone,[citation needed] and is considered a pioneer in the research area of organocatalysis.[5] In a recent review of the Hajos–Parrish–Eder–Sauer–Wiechert reaction as a name reaction, Daniel Zerong Wang describes it, and its synonyms, thus:<templatestyles src="Template:Blockquote/styles.css" />

"This reaction was independently reported by two groups in 1971: the group of Hajos and Parrish [citing a German patent dated 29 July 1971[6]] and the group of Eder, Sauer, and Wiechert [citing a German patent dated October 7, 1971, and a 1971 journal report in German and English translation[7][8][9]]. It is an enantioselective [a]ldol [r]eaction catalyzed by (S)-proline… [and is] one of the earliest enantioselectively catalyzed reactions of practical use in synthetic organic chemistry. Owing to its wide application in organic synthesis, it has been extensively explored and extended to asymmetric [a]ldol... α-alkylation… Mannich... Michael [a]ddition... and α-amination… [reactions] of carbonyl compounds. In the literature, this reaction has been referred to by different names: [as the Hajos–Parrish–Eder–Sauer–Wiechert reaction]... Hajos-Eder-Sauer-Wiechert... Hajos-Wiechert... and Hajos-Parrish-Wiechert reactions."[10]

Benjamin List, a leader in the modern field of organocatalysis,[citation needed] describes the importance of the discovery of the Hajos–Parrish–Eder–Sauer–Wiechert reaction thus:<templatestyles src="Template:Blockquote/styles.css" />

"Discovered in the early 1970s, the Hajos–Parrish–Eder–Sauer–Wiechert reaction, a proline-catalyzed intramolecular aldol reaction [citing journal articles Hajos & Parrish (1974a) and Eder, Sauer & Wiechert (1971b)[8][11]], represents not only the first asymmetric aldol reaction invented by chemists but also the first highly enantioselective organocatalytic transformation.[12]

Awards and recognition

Hajos received a Certificate of Merit, an Iron Award, from TU Budapest in May 2013, in recognition of 65 years of professional service.[citation needed]

Selected publications

The research activity of Hajos resulted in 45 scientific publications in technical journals, as well as in more than 30 patents.[citation needed] Some selected publications are:

  • R. Malathi, D. Rajagopal, Z. G. Hajos, S. Swaminathan: "Proline-catalysed asymmetric ketol cyclizations: The template mechanism revisited," Journal of Chemical Sciences, 116 (2004) pp. 159−162, doi:10.1007/BF02708219.
  • Z. G. Hajos, D. R. Parrish: "Asymmetric synthesis of bicyclic intermediates of natural product chemistry," Journal of Organic Chemistry 39 (1974), pp. 1615−1621, doi:10.1021/jo00925a003.
  • Z. G. Hajos, D.R. Parrish: "Synthesis and conversion of 2-methyl-2-(3-oxobutyl)-1,3-cyclopentanedione to the isomeric racemic ketols of the [3.2.1]bicyclooctane and of the perhydroindane series," Journal of Organic Chemistry 39 (1974), pp. 1612−1615, doi:10.1021/jo00925a002.
  • Z. G. Hajos, D. R. Parrish: (+)-(7aS)-7a-METHYL-2,3,7,7a-TETRAHYDRO-1 H-INDENE-1,5-(6H-DIONE). Organic Syntheses, Coll. Vol. 7, 363, doi:10.15227/orgsyn.063.0026.
  • Edward C. Kendall, Zoltan G. Hajos: TETRAHYDRO-3,4-FURANDIONE. I. PREPARATION AND PROPERTIES, J. Am. Chem. Soc. 82 (1960), 3219-3220, doi:10.1021/ja01497a059.
  • Z. G. Hajos, N. Cohen, D. R. Parrish, L. A. Portland, W. Sciamanna, M. A. Scott, P. A. Wehrli, 1975, "Total syntheses of optically active 19-norsteroids: (+)-estr-4-ene-3,17-dione and (+)-13β-ethylgon-4-ene-3,17-dione," Journal of Organic Chemistry 40, pp. 675−681, PMID 1133631.
  • J. B. Press, R. Falotico, Z. G. Hajos, R. A. Sawyers, R. M. Kanojia, L. Williams, B. Haertlein, J. A. Kauffman, C. Lakas-Weiss, J. J. Salata: Synthesis and structure-activity relationship of 6-substituted purine derivatives as novel selective positive inotropes, Journal of Medicinal Chemistry 35 (1992) 4509-4515, doi:10.1021/jm00102a001.

References

  1. ↑ Claude Agami, Jaques Levisalles, Catherine Puchot: "A new diagnostic tool for elucidating the mechanism of enantioselective reactions. Application to the Hajos-Parrish reaction", J. Chem. Soc., Chem. Commun. 1985, 441–442, doi:10.1039/C39850000441.
  2. ↑ 2.0 2.1 http://www.ch.bme.hu/document/1046/original/2013_Hajos_vd.pdf
  3. ↑ www.history.com/this-day-in-history/soviets-put-brutal-end-to-hungarian-revolution
  4. ↑ László Kürti, Barbara Czakó: Strategic Applications of Named Reactions in Organic Synthesis. Elsevier Academic Press, Burlington/San Diego/London 2005, ISBN 0-12-369483-3, p. 192-193.
  5. ↑ Jonathan Clayden, Nick Greeves, Stuart Warren: Organische Chemie, Springer Spektrum, 2013, 2. Auflage, pp. 1240−1241. ISBN 978-3-642-34715-3.
  6. ↑ Hajos, Z. G. and Parrish, D. R., Ger. Pat., July 29, 1971, DE 2102623, (priority date Jan. 21, 1970).
  7. ↑ Eder, U.; Sauer, G. and Wiechert, R., Ger. Pat., Oct 7, 1971a, DE 2014757.
  8. ↑ 8.0 8.1 Eder, U.; Sauer, G.; Wiechert, R., 1971b, "New Type of Asymmetric Cyclization to Optically Active Steroid CD Partial Structures," Angew. Chem. Int. Ed. Engl., 10(7), pp. 496-497, doi:10.1002/anie.197104961.
  9. ↑ Eder, U.; Sauer, G.; Wiechert, R., 1971c, "Neuartige asymmetrische Cyclisierung zu optisch aktiven Steroid-CD-Teilstücken," Angew. Chem., 83(13), pp. 492-493, doi:10.1002/ange.19710831307.
  10. ↑ Zerong Wang, 2010, "290. Hajos-Parrish-Eder-Sauer-Wiechert Reaction," in Comprehensive Organic Name Reactions and Reagents, pp. 1305-1309, New York, NY, USA:John Wiley & Sons, doi:10.1002/9780470638859.conrr290.
  11. ↑ Hajos, Z.G. & Parrish, D.R., 1974a, "Asymmetric synthesis of bicyclic intermediates of natural product chemistry," Journal of Organic Chemistry 39 (12), pp. 1615−1621, doi:10.1021/jo00925a003.
  12. ↑ Benjamin List, Linh Hoang & Harry J. Martin, 2004, "Asymmetric catalysis special feature, Part II: New mechanistic studies on the proline-catalyzed aldol reaction, Proc. Natl. Acad. Sci. USA 20 April, 5839-5842, doi:10.1073/pnas.0307979101.
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