Hajos remained there until accepting a position as assistant professor in organic chemistry at the TU Budapest in 1948, where he stayed until 1952, then as Lecturer at the University of Veszprem, returning as a Research Associate at the Institute of Organic Chemistry at TU Budapest in 1953. With backlash following the 1956 Revolution in October, 1956, 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.
Hajos–Parrish–Eder–Sauer–Wiechert reaction, discovery and importance
Hajos is noted for the Hajos–Parrish–Eder–Sauer–Wiechert reaction, and of the related -proline-catalyzed synthesis route to the Hajos-Wiechert ketone, and is considered a pioneer in the research area of organocatalysis. 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: Benjamin List, a leader in the modern field of organocatalysis, describes the importance of the discovery of the Hajos–Parrish–Eder–Sauer–Wiechert reaction thus:
The research activity of Hajos resulted in 45 scientific publications in technical journals, as well as in more than 30 patents. 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 pp. 159−162,.
Z. G. Hajos, D. R. Parrish: "Asymmetric synthesis of bicyclic intermediates of natural product chemistry," Journal of Organic Chemistry39, pp. 1615−1621,.
Z. G. Hajos, D.R. Parrish: "Synthesis and conversion of 2-methyl-2--1,3-cyclopentanedione to the isomeric racemic ketols of the bicyclooctane and of the perhydroindane series," Journal of Organic Chemistry39, pp. 1612−1615,.
Z. G. Hajos, D. R. Parrish: --7a-METHYL-2,3,7,7a-TETRAHYDRO-1 H-INDENE-1,5-. Organic Syntheses, Coll. Vol. 7, 363,.
Edward C. Kendall, Zoltan G. Hajos: TETRAHYDRO-3,4-FURANDIONE. I. PREPARATION AND PROPERTIES, J. Am. Chem. Soc. 82, 3219-3220,.
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 Chemistry40, pp. 675−681,.
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 Chemistry35 4509-4515,.