Diethyl azodicarboxylate,

DBPO DBU DCC DDQ DEAD DET DIBAL-H DIPT DMAP DMB DME DMF DMPU DMSO EDDA Eu(dppm)3 Eu(fod)3 dibenzoyl peroxide 1.8- diazabicyclo [ 5.4.0] undec-7-ene dicyclohexylcarbodiimide 2.3- dichloro-5,6-dicyano-l,4-benzoquinone diethyl azodicarboxylate diethyl tartrate diisobutylaluminium hydride diisopropyl tartrate iMM-dimethylaminopyridine 3.4- dimethoxybenzyl 1.2- dimethoxyethane dimethylformamide 1.3- dimethyl-3,4,5,6-tetrahydro-2(lH)pyrimidinone dimethyl sulfoxide ethylene diammonium diacetate di(perfluoro-2-propoxypropionyl)methanato europium 6.6.7.7.8.8.8- heptafluoro-2,2-dimethyl-3,5-octanedionato... 

To prepare fervenulin 4-oxides 12 or toxoflavine 4-oxides 146, it is convenient to use the reaction of l,3-dimethyl-2,4-dioxopyrimidin-6-yl hydrazone 147 or N-(3-methyl-2,4-dioxopyiimidin-6-yl) iV-methylhydrazone 148 with potassium nitrate in acetic acid [75CPB1885,76CPB338,76JCS(CC)658,82JHC1309,93CPB362]. Diethyl azodicarboxylate can be used instead of potassium nitrate [76JCS(P1 )713]. 

The mechanistic pathway" " can be divided into three steps 1. formation of the activating agent from triphenylphosphine and diethyl azodicarboxylate (DEAD) or diisopropyl azodicarboxylate (DIAD) 2. activation of the substrate alcohol 1 3. a bimolecular nucleophilic substitution (Sn2) at the activated carbon center. 

In an initial step triphenylphosphine adds to diethyl azodicarboxylate 5 to give the zwitterionic adduct 6, which is protonated by the carboxylic acid 2 to give intermediate salt 7. The alcohol reacts with 7 to the alkoxyphosphonium salt 8 and the hydrazine derivative 9, and is thus activated for a SN2-reaction ... 

The conversion of an alcohol to an amine can be achieved in a one-pot reaction the alcohol 1 is treated with hydrazoic azid (HN3), excess triphenylphosphine and diethyl azodicarboxylate (DEAD). The initial Mitsunobu product, the azide 14, further reacts with excess triphenylphosphine to give an iminophosphorane 15. Subsequent hydrolytic cleavage of 15 yields the amine—e.g. as hydrochloride 16 ... 

The Mitsunobu reaction was also applied to the synthesis of [ 1,2,4]triaz-ino[4,5-n]indoles (84AG517). Thus, reaction of the 2-acylindoles 127 with sodium borohydride in methanol or with lithium aluminium hydride in tetrahydrofuran gave the corresponding alcohols 128. Their cyclization with diethyl azodicarboxylate in the presence of triphenyl-phosphine gave the triazinoindoles 129. Acid treatment of the latter afforded 130 (Scheme 30). 

Treatment of 6-arylidenehydrazino-3-alkyl-5-nitrouracils 510 with etha-nolic KOH caused a benzylic acid type of rearrangement to give 511, which were alkylated to give 512, whose cyclization with diethyl azodicar-boxylate gave (80H1295) 513 by intramolecular cycloaddition through valence isomerization and then aromatization with diethyl azodicarboxylate (Scheme 107). 

Cydization of P-hydroxy-a-amino esters under Mitsunobu reaction conditions is an alternative approach to aziridine-2-carboxylic esters [6b, 13-16], In this case the P-hydroxy group is activated by a phosphorus reagent. Treatment of Boc-a-Me-D-Ser-OMe 13 (Scheme 3.5) with triphenylphosphine and diethyl azodicarboxylate (DEAD), for example, gave a-methyl aziridinecarboxylic acid methyl ester 14 in 85% yield [15]. In addition to PPh3/DEAD [13b, 15], several other reagent combi-... 

Rzdtc) ] reacts with diethyl azodicarboxylate, azobenzene, or dimethyl acetylenedicarboxylate to give the appropriate hydrazine and disulfide... 

Unsymmetrical disulfides can be prepared by treatment of a thiol RSH with diethyl azodicarboxylate (EtOOCN=NCOOEt) to give an adduct, to which another thiol R SH is then added, producing the disulfide RSSR. ... 

Mercaptans have been oxidized with diethyl azodicarboxylate and triphenylphosphine. It is suggested that the formation of a charge-transfer complex (57) may be a key step in the reaction. 

A variety of reagents can function as the electrophile E+ in the general mechanism. The most useful synthetic procedures for preparation of halides are based on the halogens, positive halogens sources, and diethyl azodicarboxylate. A 1 1 adduct formed from triphenylphosphine and bromine converts alcohols to bromides.15 The alcohol displaces bromide ion from the pentavalent adduct, giving an alkoxyphosphonium intermediate. The phosphonium ion intermediate then undergoes nucleophilic attack by bromide ion, forming triphenylphosphine oxide. 

A very mild procedure for converting alcohols to iodides uses triphenylphosphine, diethyl azodicarboxylate (DEAD), and methyl iodide.24 This reaction occurs... 

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