In memoriam Henk van der Plas

Education

Henk was born in Voorhout on 4 May 1929, grew up in Haarlem, and obtained his gymnasium diploma in 1947. Subsequently, he worked for several years as an analyst at the steel manufacturer Hoogovens. In 1951, he began studying physics and mathematics at the University of Amsterdam and obtained his 'doctoraalexamen' (master's degree equivalent) in 1956, with chemistry as his major subject. Afterwards, he went to the (then) Agricultural University Wageningen, initially via the Netherlands Foundation for Chemical Research (SON) and from 1958 onwards in permanent employment for teaching and research in the Laboratory for Organic Chemistry under the supervision of Prof. dr. H.J. den Hertog.

Research and Teaching 

He began research on heterocyclic compounds and obtained his PhD on 6 July 1960 in Amsterdam with the thesis 'Sulfonation of pyridine and pyridine derivatives in which the nitrogen is shielded by bulky alkyl groups'. After obtaining his doctorate, he worked for a year from 1960-1961 in the laboratory of Prof. dr. R.H. Wiley in Louisville, USA. 

After Den Hertog's retirement, Henk van der Plas succeeded him in 1971 as Professor of Organic Chemistry and continued to publish in the field of heterocyclic chemistry. He discovered that the substitution of halogen atoms by amines in heterocyclic systems proceeded via ring opening and reclosure. This so-called ANRORC mechanism was a previously unknown way for chemical compounds to react. He also studied the cyclo-addition of alkenes to tetrazines, a reaction now known as an example of "click chemistry". Click chemistry is widely used in chemical biology, and the Nobel Prize for it was awarded in 2022. Furthermore, Henk was one of the first in the world to recognise the importance of using enzymes as catalysts in chemical reactions. His research resulted in over 400 publications and 3 books. He had many contacts, particularly in Eastern Europe, and received honorary doctorates from a number of European universities (Wrocław, Leuven, Prague, Krakow, Gödöllö, Moscow). In 1993, he was appointed a member of the Russian Academy of Sciences. 

In total, Henk supervised 28 PhD candidates between 1973 and 1993. In the current era, this may seem few. However, it should be noted that in the 70s and 80s, there were fewer opportunities for sponsoring scientific research than now, and most first-stream funding was used for permanent staff due to the enormous growth in the number of students at that time. He was an enthusiastic supervisor for his PhD candidates, granting them considerable freedom and initiative. 

Governance and Internationalisation 

From the 1970s, Henk also became active as an administrator, first as group leader of the SON working communities Organic Synthesis and Organodynamics, later also as (vice-)chairman of the Royal Netherlands Chemical Society (KNCV). The "Wageningen congress" of the Organic Chemistry section of the KNCV, which he co-initiated, still exists. He also served as chairman of the Netherlands University Foundation for International Cooperation (NUFFIC). From 1977-1981 and from 1988-1993, Henk was Rector Magnificus in Wageningen. During this period, he actively promoted internationalisation, initiating contacts with Asian (Vietnam, Indonesia), South American (Costa Rica, Suriname), and South African universities. In those turbulent 80s, these collaborations were occasionally controversial. 

In the 90s of his rectorship, Henk was actively involved in the establishment of the Wageningen research schools. Also, upon invitation, he evaluated the quality of education and research at the agricultural universities of Uppsala (Sweden) and Prague (Czech Republic) with a team of Wageningen experts. These contacts contributed to the establishment of UniverCities in 1992, a collaboration between cities with an agricultural university: Uppsala, Prague, Hohenheim, Gödöllö, and Wageningen. Although this specific international collaboration has ceased, the current Food Valley Award stems from it. 

How important internationalisation was to Henk is also evident from his farewell speech as rector at the Dies in 1993: 'On the way to a European agricultural university'. In his speech, he outlined a route towards what eventually became Wageningen University. At his farewell, he was appointed Commander in the Order of Orange-Nassau. This was the second royal honour, following the appointment as Knight in the Order of the Netherlands Lion received in April 1988. 

Privately, Henk was also active as an administrator, specifically as (vice-)chairman of the Supervisory Board of Cordaid. In 2002, he received a papal honour for this, in the order of Saint Gregory the Great. In the portrait gallery in Omnia, the building for PhD defences at Wageningen University, hangs a painted portrait of him. He is depicted rather formally in it, whereas in reality, he was a particularly warm personality.