Categories: C-N Bond Formation >
Synthesis of Hydrazine Derivatives (Hydrazides)
An efficient method for the direct reductive alkylation of hydrazine derivatives with α-picoline-borane provided various N-alkylhydrazine derivatives upon fine-tuning of the substrates and the reagent equivalency in a one-pot manner. The method was applied to the synthesis of active pharmaceutical ingredients of therapeutic drugs such as isocarboxazid.
Y. Kawase, T. Yamagishi, J.-y. Kato, T. Kutsuma, T. Kataoka, T. Iwakuma, T. Yokomatsu, Synthesis, 2014, 46, 455-464.
Lewis base promoted direct reductive hydrazination enables a straightforward and facile synthesis of 1,1-disubstituted hydrazines with very good yields. Under the catalysis of hexamethylphosphoramide (HMPA) and N,N-dimethylacetamide (DMAc), respectively, various ketones and aldehydes reacted with phenylhdrazines.
T. Wang, X. Di, C. Wang, L. Zhou, J. Sun, Org. Lett., 2016, 18, 1900-1903.
CuI/4-hydroxy-l-proline-catalyzed coupling of aryl bromides and N-Boc hydrazine takes place in DMSO to give N-aryl hydrazides. When aryl iodides are employed, no ligand is required. Under the catalysis of CuI/4-hydroxy-l-proline, the coupling reaction of aqueous ammonia with aryl bromides proceeds smoothly to afford primary arylamines.
L. Jiang, X. Lu, H. Zhang, Y. Jiang, D. Ma, J. Org. Chem., 2009, 74, 4542-4546.
CuI-catalyzed coupling of N-acyl-N′-substituted hydrazines with aryl iodides affords N-acyl-N′,N′-disubstituted hydrazines regioselectively. N-Acyl-N′-substituted hydrazines can also react with 2-bromoarylcarbonylic compounds in the presence of 4-hydroxy-L-proline as ligand to provide 1-aryl-1H-indazoles.
X. Xiong, Y. Jiang, D. Ma, Org. Lett., 2012, 14, 2552-2555.
The use of a catalytic amount of palladium, a MOP-type ligand, and Cs2CO3 enables a convenient method for the intermolecular N-arylation of hydrazides with aryl halides. The reaction gives coupled products in very good yields and tolerates a wide spectrum of functional groups.
F.-F. Ma, Z.-Y. Peng, W.-F. Li, X.-M. Xie, Z. Zhang, Synlett, 2011, 2555-2558.
A copper-catalyzed addition of arylboronic esters to di-tert-butyl azodicarboxylate affords Boc-protected arylated hydrazine derivatives in good yields under mild reaction conditions. The reaction tolerates various functional groups.
T. Uemura, M. Yamaguchi, N. Chatani, Synthesis, 2015, 47, 3746-3750.
Copper(I) oxide catalyzes an efficient intermolecular N-arylation of the anionic species derived from diisopropyl azodicarboxylate and sodium hydride with various aryl trifluoromethanesulfonates without ligand at 80 °C in N,N-dimethylformamide.
I. Yavari, M. Ghazanfarpour-Darjani, M. J. Bayat, A. Malekafzali, Synlett, 2015, 26, 942-944.
A gold(III) chloride catalyzed direct amination of arenes with azodicarboxylates allows the conversion of a broad range of substrates, including electron-deficient arenes, under mild conditions. This reaction provides an important approach for the synthesis of heterocyclic compounds in pharmaceutical and chemical industries.
L. Gu, B. S. Neo, Y. Zhang, Org. Lett., 2011, 13, 1872-1874.
Alkylation of hydrazine using a polyanion strategy provides a fast and convenient access to multialkylated hydrazine derivatives. Scope and limitations of the new method are also investigated.
A. Bredihhin, U. Mäeorg, Org. Lett., 2007, 9, 4975-4977.
Formation and use of a nitrogen dianion for selective hydrazine alkylation provides a fast and easy access to substituted hydrazines, which are widely used as drugs, pesticides, and precursors for a variety of compounds in organic synthesis.
A. Bredihhin, U. M. Groth, U. Mäeorg, Org. Lett., 2007, 9, 1097-1099.
A mild, copper-catalyzed addition of aryl- and heteroarylboronic acids to azo compounds is described. Excellent regioselectivity was observed in the addition to unsymmetrical azo compounds.
K. Kisseljova, O. Tšubrik, R. Sillard, S. Mäeorg, U. Mäeorg, Org. Lett., 2006, 8, 43-45.
Excellent regioselectivity is observed in the addition of diverse organometallic nucleophiles to unsymmetrical azo compounds. Primary/secondary/tertiary alkyl, aryl and heteroaryl substituents were introduced this way in high yields.
O. Tšubrik, R. Sillard, U. Mäeorg, Synthesis, 2006, 843-846.
A ligand-to-metal charge transfer (LMCT) excitation-homolysis process with an abundant and inexpensive cerium salt as the catalyst enables a direct catalytic generation of energetically challenging alkoxy radicals from alcohols. This catalytic manifold provides a simple and efficient way for versatile a δ-selective C-H bond functionalization under mild redox-neutral conditions.
A. Hu, J.-J. Guo, H. Pan, H. Tang, Z. Gao, Z. Zuo, J. Am. Chem. Soc., 2018, 140, 1612-1616.
In situ aerobic dual oxidation with asymmetric organocatalysis enables an enantioselective synthesis of α-hydrazino aldehydes from alcohols and N-Boc hydrazine instead of the conventional combination of aldehydes with azodicarboxylates. This reaction tolerates various substituents on the alcohol component and features excellent enantiocontrol, cheap starting materials, operational simplicity, and scalability.
Z. Cui, D.-M. Du, Org. Lett., 2016, 18, 5616-5619.
Mercuric triflate [Hg(OTf)2] as a catalyst enables an efficient method for carbon-nitrogen bond formation between ally silyl ethers and N,N-acyltosylhydrazine under very mild conditions to yield various N-allylhydrazides in very good yields. This method does not require the use of any ligand system or supplementary additives.
M. Hayashi, M. Shibuya, Y. Iwabuchi, Synlett, 2012, 23, 1025-1030.
A highly chemo- and regioselective allylic amination of various hydrazones and hydrazides with allylic carbonates proceeds at ambient temperature in the presence of an [Ir(COD)Cl]2/pyridine catalyst, ammonium iodide, and diethylzinc to afford the corresponding N-allylation products in high yields.
R. Matunas, A. J. Lai, C. Lee, Tetrahedron, 2005, 61, 6298-9308.
FeCl3 mediates a propargylic substitution of tertiary propargylic alcohols with p-toluenesulfonyl hydrazide. A subsequent cyclization under mild conditions in the presence of iodine enables an efficient and rapid synthesis of iodo-3H-pyrazoles with a wide substrate scope and in high yields.
X.-T. Liu, Z.-C. Ding, L-C. Ju, Z.-N. Tang, F. Wu, Z.-P. Zhan, Synlett, 2017, 28, 620-624.