Valentine G. Nenajdenko

Isocyanoacetate Derivatives: Synthesis, Reactivity, and Application

The sphingolipid bases, D-erythro- and D-threo-sphingosines, are the target molecules that have been synthesized to demonstrate the efficiency of a new methodology to control both absolute and relative configurations in acyclic systems. Tubulysins are compounds of extraordinary potency, rapidly degrading the tubulin cytoskeleton, with tubulysin D being the most active tubulin-modifier known so far. Among other isonitriles, isocyanoacetate derivatives occupy an important place in the field of synthetic application and reaction diversity, which makes them strongly attractive objects for investigation. The unique multifunctional nature of isocyanoacetic acid derivatives opens up a range of exciting reactions, especially tandem/cascade processes for the synthesis of complex cyclic and macrocyclic systems. Multicomponent chemistry of isocyanoacetates is also a powerful instrument to access different classes of biochemically relevant compounds such as peptides, peptide molecules, and nitrogen heterocycles.

Polyfluorinated Ethanes as Versatile Fluorinated C2-Building Blocks for Organic Synthesis

for Organic Synthesis Valentine G. Nenajdenko,*,†,§ Vasiliy M. Muzalevskiy,† and Aleksey V. Shastin†,‡ †Department of Chemistry, Moscow State University, Leninskie Gory, Moscow 119992, Russia ‡The Institute of Problems of Chemical Physics of the Russian Academy of Sciences (IPCP RAS), Chernogolovka, Moscow Region 142432, Russia A.N. Nesmeyanov Institute of Organoelement Compounds of Russian Academy of Sciences (INEOS RAS), 119991, GSP-1, Moscow, V-334, Vavilova St. 28, Russia

Recent advances in the Cu(I)-catalyzed azide–alkyne cycloaddition: focus on functionally substituted azides and alkynes

First described by the groups of Sharpless (Rostovtsev et al., Angew. Chem., Int. Ed., 2002, 41, 2596) and Meldal (Tornoe et al., J. Org. Chem., 2002, 67, 3057) in 2002, Cu(I)-catalyzed azide–alkyne cycloaddition (CuAAC) became one of the most effective and reliable synthetic tools in diverse areas of modern chemistry, such as organic, medicinal and polymer chemistry, material science and chemical biology. The advantages of this reaction are high selectivity, simple reaction conditions, wide scope and excellent functional group tolerance. This efficient transformation can be used for the synthesis of various 1,2,3-triazoles. On the other hand, CuAAC can be efficiently used for bioconjugation of two units bearing alkyne and azide functions via the triazole moiety. Moreover, the use of azides and alkynes bearing orthogonal functional groups in this reaction opens broad opportunities for the synthesis of valuable polyfunctionalized triazole-containg molecules. Thus, the initial discussion is focused on synthetic applications of functionally substituted azides and terminal alkynes in the CuAAC, combined with other transformations. The prominent part of this review is devoted to an application of these bi (or tri)-functional reagents for the design, synthesis or labeling of biologically active molecules.

A novel approach to fluoro-containing alkenes

A new and general one-pot transformation of aromatic aldehydes to fluorinated olefins containing –CHC(Cl)CF3 or –CHC(F)CClF2 moieties is described. Freons CCl3CF3 and CCl2FCClF2 were used as trifluoromethyl and difluoromethyl C2-building blocks respectively. A proposed mechanism for the reaction is discussed.

Preparation of α, β-Unsaturated Ketones Bearing a Trifluoromethyl Group and Their Application in Organic Synthesis

, Andrei V. Sanin, Elizabeth S. BalenkovaDepartment of Chemistry, Moscow State University, 119899 Moscow, RussiaTel.: +7 (095) 939-43-94; Fax: +7 (095) 932-88-46; E-mail: Nen@acylium.chem.msu.suReceived: 9 December 1996 / Accepted: 28 March 1997 / Published: 1 December 1997Abstract: The approaches to the synthesis of α,β-unsaturated CF

Nonracemizable Isocyanoacetates for Multicomponent Reactions

Chiral ortho esters of alpha-isocyano acids were synthesized from commercially available Cbz-protected alpha-amino acids. These compounds are stable toward racemization in the Ugi 4CC in contrast to known esters of alpha-isocyano acids. Applying them in Ugi 4CC with subsequent deprotection gives access to dipeptides with preserved configuration at the C-terminal amino acid.

A Novel Synthetic Approach to Dichlorostyrenes

Abstract We found that N -unsubstituted hydrazones of aromatic aldehydes can be easily converted to the corresponding 1,1-dichlorostyrenes in the reaction with carbon tetrachloride using copper (I) chloride as catalyst. Factors affecting the route of the reaction and yields of the products were investigated. A proposed mechanism for the reaction is discussed.

3‐Trifloxy‐3‐trifluoromethylpropeniminium Triflate: Reaction with Aromatic Amines – An Efficient Synthesis of 2‐Trifluoromethylquinolines

The reaction of iminium triflates 2 and 7 with various aromatic amines were investigated. The 2-Rf-substituted quinolines 3 and 8 were prepared in excellent yields by the reaction of 2 and 7, respectively, with substituted anilines. The reactions of 2 and 7 with diarylamines proceeds, suprisingly, to afford the corresponding 3-Rf-substituted cinnamaldehydes 4 and 9.

A novel direct synthesis of (2,2-difluorovinyl)benzenes from aromatic aldehydes

A novel catalytic approach to (2,2-difluorovinyl)benzenes has been developed. It was found that hydrazones of aromatic aldehydes generated in situ could be converted to the corresponding (2,2-difluorovinyl)benzenes by catalytic olefination reaction (COR) with dibromodifluoromethane in the presence of CuCl.

Novel efficient synthesis of dibromoalkenes. A first example of catalytic olefination of aliphatic carbonyl compounds

A new simple and efficient one pot transformation of various aliphatic carbonyl compounds to the corresponding dibromoalkenes is described. A wide range of hydrazones of aldehydes and ketones, prepared in situ, were easily converted into dibromoalkenes by treatment with carbon tetrabromide in the presence of CuCl. The reaction proceeds under mild conditions to give the target products in good to high yields.