With the departure of Markovnikov the chair of organic chemistry and the direction of the chemistry school at the University of Kazan passed to Aleksandr Mikhailovich Zaitsev, of whom Butlerov had written to the dean of the faculty in 1869, "Based on the results of his work, A.M. Zaitsev occupies one of the first places among young Russian chemists who do not yet have an academic position."
Like his mentor, Butlerov, and his contemporary, Markovnikov,
Zaitsev was the mentor of several important organic chemists, including
Reformatsky, Wagner, and Arbuzov. But, unlike many of his contemporaries
(e. g., Markovnikov and Demyanov), Zaitsev did not receive early recognition
for his work (even as recently as the 1960's, few textbooks in organic
chemistry bothered to put his name on Zaytsev's rule, and his contributions
to the development of chemistry in Russia were overshadowed, perhaps unfairly
so, by those of Markovnikov). In part, this may be due to the fact that
he spent his entire career at Kazan, rather than moving to Moscow or St.
Zaitsev was born in a mercantile family, and his father wanted him to follow in his footsteps. However, Zaitsev's maternal uncle, the astronomer Mikhail Lyapnbov, convinced his brother-in-law that Zaitsev should enter the university, and personally taught his nephew the Latin required to enter the study of law. Zaitsev graduated from the University of Kazan in 1862 with a degree in law, although the two years of chemistry required (taught by Butlerov) so captivated him that he decided upon chemistry rather than law as a career. Immediately following his graduation, he broke with tradition by going abroad to study chemistry before completing his dissertation for the degree of kandidat. His first stop abroad was at the University of Marburg, where he studied under Hermann Kolbe. In 1863 he also submitted his kandidat's dissertation (on Kolbe's structural theory) to the University of Kazan. The degree was not awarded.
At Marburg, he began work with the chemistry of organic sulfides that led to his discovery of the sulfoxides (1). In August 1864, he travelled to Paris, where he spent nine months in the laboratories of Aldolphe Wurtz, studying the nitration of aromatics and the chemistry of cyanoacetic ester (2). He returned to Marburg in May 1865, where he continued his work with organic sulfides. However, when Kolbe accepted the chair of chemistry at Leipzig, Zaitsev chose to return to Kazan. In 1866 he did send his published papers to the University of Leipzig in the form of a dissertation and, thanks to Kolbe's support, he was awarded his PhD by that university.
On his return to Kazan, Zaitsev first worked as an unpaid laboratory assistant for Butlerov. As soon as he had obtained his kandidat degree, Butlerov secured a junior position for him on the faculty as a laboratory technologist in agronomic chemistry, although it was fairly obvious that he would assume a position in the chemistry department as soon as one became available. His Kandidat's and Master's dissertations at Kazan were presented in 1865 and 1867. Both clearly showed the influence of his time with Kolbe. They described chemistry of thioethers and their reactions with nitric acid (the first report of the preparation of sulfoxides, (1) and methyl iodide (3). He presented his doctoral dissertation on the transformations of alcohols in 1870.
Zaitsev's independent research program after his return to Russia reflected the influence of Butlerov on Russian chemistry at this time. Zaitsev remained true to the course set by his mentor (Russian sources speak of the "Butlerov-Zaitsev school"), and he attracted many of the finest young chemists in Russia. Thus, many of Zaitsev's papers concerned the development of synthetic methods based upon the reactions of zinc alkyls with carbonyl compounds. The synthesis of tertiary alcohols had been one of Butlerov's early triumphs. With his student Egor Egorevich Vagner, Zaitsev developed a general method for the synthesis of secondary alcohols from aldehydes and zinc alkyls (4).
Zaitsev was a productive worker. In addition to his discovery of the sulfoxides, he reported the first preparation of butyrolactone (5). However, it was his paper (published under the German spelling of his name, Saytzeff) in Justus Liebigs Annalen der Chemie in 1875 (6) that has led to his enduring fame in sophomore organic chemistry textbooks. In 1885, he became a corresponding member of the Academy of Science, and in 1903 he was appointed an honorary member of the faculty of Kiev University, possibly at the urging of his student Aleksandr Nikolaevich Reformatsky, who was professor of chemistry at Moscow University and who probably influenced his more famous brother, Sergei Nikolaevich, to support the nomination.
Although Markovnikov's departure had left a large gap in the chemistry research program at Kazan Zaitsev's research group continued the Kazan tradition of attracting some of the finest minds of the next generation. Among these were Sergei Nikolayevich Reformatskii (or Reformatsky), Egor Egorevich Vagner (better known under the German spelling of his name, Wagner), and Aleksandr Erminingeldovich Arbuzov.
Egor Egorevich Vagner (1849-1903) was one of the founders of the field of terpene chemistry. Like his mentor before him, Vagner began his studies at the University of Kazan as a student in law (1867-1868), where he heard chemistry lectures by both Markovnikov and Zaitsev. After two years in the study of law, he transferred to the Physics-Mathematics Department, where he carried out research under Zaitsev (4b). Among his papers was a method for the synthesis of secondary alcohols by the reaction between aldehydes and zinc alkyls.
Until the development of strong, non-nucleophnic amide bases in 1970’s rendered the formation of preformed lithium enolates practical, the Reformatsky reaction was the major method for forming b-hydroxycarbonyl compounds, and was one of the few such reactions that did not lead to concomitant dehydration of the product. Although the resurgence of the aldol condensation has somewhat eclipsed the Reformatsky reaction as the method of choice for the synthesis of such compounds, the reaction is still used in appropriate circumstances. On his return to Russia, in 1891, he was appointed professor of chemistry at the University of Kiev, where he continued his research into the reactions of alkylzinc halides (14, 15). In 1891, he wrote a textbook of organic chemistry that went through three editions (16). In 1928, Reformatsky was made a corresponding member of the USSR Academy of Science.
One of the last students to study under Zaitsev at Kazan was Aleksandr Erminingeldovich Arbuzov (1877-1968). He graduated from the University of Kazan in 1900, and then followed the path another former Zaitsev student, Egor Egorevich Vagner, as assistant in chemistry (1901), and then Adjunct Professor of Chemistry (1906) at the Novo-Aleksandria Institute of Agriculture and Forestry. In 1911, he succeeded his mentor as professor of chemistry at Kazan, a position he held from 1911 to 1930. In 1922, he was elected Deputy Dean of the physics-mathematics faculty. In 1930, Arbuzov became professor at the Kazan Chemical-Technological Institute, where he remained for the rest of his professional career.
Arbuzov's research work concerned the chemistry of organo-phosphorus compounds, and as part of his master's thesis in 1905 (17) he determined the structure of phosphorous acid and its esters. This work resolved the controversy over the number of hydroxyl groups in the acid and showed the structural differences between phosphorus acid (in which the phosphorus is tetracoordinate and has a PH bond) and the trialkyi phosphites (in which the phosphorus is tricoordinate). He subsequently discovered the rearrangement of phosphite esters to phosphonic acid esters (18), a reaction that has assumed major importance with the development of the Wadsworth-Emmons olefination reaction (19). His name also has become attached to the Michae-lis-Arbuzov reaction, which was discovered by Michaelis and Kaehne in 1898 (20), but much more intensely studied by Arbuzov in the early decades of the 20th century. In collaboration with his son and student, Boris Aleksandrovich Arbuzov (himself a prominent Russian chemist), he developed a new method for the formation of triarylmethyl radicals from triarylmethyl halides and phosphite anions.
During World War II, the members and laboratory equipment
of the Moscow and Leningrad (now St. Petersburg) Academies of Science were
evacuated to Kazan (21). The rise of the Kazan Institute
as a large research institution dates from this time (22). When the 25th
anniversary of the Kazan branch of the Soviet Academy of Science was celebrated
in 1945, Arbuzov was among a speaker list that included such luminaries
as the Joliot-Curies, Robinson, Langmuir, and Svedberg. Arbuzov won numerous
awards, including two Stalin Prizes, and he was on several occasions a
delegate to the Supreme Soviet (the governing body of the Soviet Union).
He was also a historian and wrote a history of chemistry (23) that emphasized
the contributions of the Kazan school to the development of Russian chemistry.
The influence of Kazan may be best gauged by examining the figure, where the genealogy of Russian chemistry beginning at Kazan is traced. All the chemists whose names appear in boldface earned their undergraduate or graduate degrees from the University of Kazan. Only their more well-known students are listed.
 (a) Saytzeff, A. Ann. Chem. Pharm, 1866. 139, 354-364; 1867. 144. 148-156, (b) Grabowsky.N.: Saytzeff. A. Ann. Chem. Pharm. 1875. 175. 348-351.
 Saytzeff. A. Ann. Chem. Pharm. 1865, 133.321-329. 329-335.
 Saytzeff, A. Ann. Chem. Pharm. 1867, 114, 145-148.
 (a)Kanonnikoff. J.; Saytzeff. A. Ann. Chem. Pharm. 1875, 175. 374-378; 1875. 179. 338. (b) Wagner, G.; Saytzeff. A. Ann. Chem. Pharm. 1875, 175. 351-374; 1875, 179. 302-313, 313-325.
 Saytzeff, A. Ann. Chem. Pharm. 1874, 171, 258-290.
 Saytzeff, A. Ann. Chem. Pharm. 1875, 179, 296-301.
 Wagner, G. Ber. Deut. chem. Ges. 1888, 21, 1230-1240, 3343-3346, 3347-3355, 3356-3360.
 Vagner, E. E. J. Russ. Phys. Chem. Soc. 1894, 26, 327-362; 1896, 28, 56-108, 206. 398, 484-501.
 Wagner, G.; Brickner. W. Ber. Deut. chem. Ges. 1899, 32, 2302-2325; 1900, 33, 2121-2125.
 Meerwein, H.; van Emster. K. Ber. Deut. chem. Ges. 1920, 53B, 1815-1829; 1922, 55B, 2500-2528.
 (a) Wagner, G. Ber. Deut. chem. Ges. 1891, 24. 2187-2190. (b) Wagner, G.; Slawinsky, K. Ber. Deut. chem. Ges. 1899, 32. 2064-2083. (c) Wagner, G.; Ginzberg, A. Ber. Deut. chem. Ges. 1896, 29, 886-890.
 Ipatieff, V. N. The Life of a Chemist: Memoirs of Vladimir N. Ipatoff, (Stanford University Press: Stanford, CA, 1946).
 Reformatsky, S. N. Reaction of the Mixture of Zinc and Ethyl Monochloroacetate with Ketones and Aldehydes (Synthesis of Tertiary b-Hydroxyacids), Dr. Chem. Dissertation, University of Warsaw, 1890 (in Russian).
 Reforroatsky, S. Ber. Deut. chem. Ges. 1887. 20, 1210-1211; 1895, 28, 2842-2847, 3262-3265.
 Reformatsky, S.; Plesconossoff. B.Ber. Deut. chem. Ges. 1895, 28, 2838-2841.
 Reformatsky, S. N. A Beginner's Course of Organic Chemistry (Kiev, 1891).
 Arbuzov, A. The Structure of Phosphorous Acid and Us Derivatives (Kazan. 1905).
 (a) Arbuzov, A. J. Russ. Phys. Chem. Soc. 1910, 42, 395-420, 549-561; Chem. Zentr. 1910, II, 463-454.
 For a review, see: Wadsworth, W. S., Jr. Org. React. 1977, 25, 74.
 Michaelis, K.; Kaehne, R. Ber. Deut. chem. Ges. 1898, 37, 1048-1055.
 Grechkin, N.P.; Kuznetsov. V. I. Aleksandr Ermininget'dovich Arbuzov 1877-1968;
(Science Publications; Moscow. 1977). [In Russian]
 A reviewer has pointed out that Kazan became a major resaerch center lover 1,000 PhD's in phosphorus chemistry I carrying out research into nerve gases, among other work. The author has not been able to verify this, but given Arbuzov's strongly nationalistic feelings for the Soviet Union, it is probably true.
 Arbuzov, A. E. A Brief Sketch of the Development of Organic Chemistry in Russia; (Academy of Science USSR, Leningrad. 1948). [In Russian]