Über die Zersetzung der Diazoketone

Abstract

Grundmann, Vber die Zersetzung der Diazoketone. 29 Wasserstoffverbrauch. 0,17 g Subst.: 44 ccm (Oo, 760 mm), fiir 2H2 ber. 40 ccm. d) 1,4,6-Trimethyl-3-athyl-5-carb0xy-pyridolz (2) aus der 3-(a-Oxyvinyl)-Verbindung. (XlX). Ausbeute 97 Proc. Das Rohprodukt wird aus 50-proc. Alkohol umkrystallisiert und schmilzt bei 211 O (Zers.). Leicht loslich in Eisessig, Alkohol, Natronlauge; schwer 1Sslich in Aceton, Essigester, Ather, Wasser. Wasserstoffverbrauch. 0,5 g Subst.: 112 ccm (00, 760 mm), ber. fur 2H, 107 ccm. 4,901 mg Subst.: 11,300 mg CO,, 3,200 mg H,O. -3,480 mg Subst.: 0,206 ccm N (24O, 755 mm).

Functionalisedcis-Alkenes from the Stereoselective Decomposition of Diazo Compounds, Catalysed by [RuCl(η5-C5H5)(PPh3)2]

“…[3] Nevertheless, the carbene-carbene coupling reaction may be useful in producing suitably designed functionalised alkenes, if carried out with efficient stereocontrol of the process. Indeed, since the pioneering studies of Grundmann, [4] generally unsatisfactory results have been obtained with diazo ketones as starting material, both for inter-and intramolecular versions of the carbene coupling process. [5Ϫ8] More recently, good yields and high cis/trans selectivity have been obtained by using group-8 metal-porphyrin complexes such as [Ru(TMP)] [9] and [Os(TTP)] 2 , [10] which decompose ethyl diazoacetate (EDA) giving diethyl maleate in 94 and 96% yield, respectively.…”

Zinc‐Catalyzed Synthesis of Conjugated Dienoates through Unusual Cross‐Couplings of Zinc Carbenes with Diazo Compounds

“…A different approach comprises the use of diazo compounds, which can be joined by carbene coupling. This archetypal reactivity of diazo compounds was not able to find a widespread applicability due to the difficulty of controlling homocoupling versus cross‐coupling processes to prepare unsymmetrically substituted alkenes (Scheme a) . In spite of this difficulty, a few remarkable examples of Rh‐ and Au‐catalyzed cross‐coupling reactions with diazo compounds have been recently reported by Davies and Sun .…”

Gold(I)‐Catalyzed Diazo Coupling: Strategy towards Alkene Formation and Tandem Benzannulation

“…Alternatively, the carbenoid‐induced coupling of diazo compounds affords another possibility 3. However, after the first discovery of this transformation,3a only a few synthetically useful processes have been reported and the most useful applications are metal‐catalyzed intramolecular coupling of bis(diazocarbonyl) compounds or their synthetic surrogates developed by the groups of Doyle,4 Che,5 and Wang 6. In contrast, the intermolecular diazo cross‐coupling might be more challenging because of the inevitable competition between homo‐ and cross‐coupling processes, as well as difficulties in controlling the stereoselectivity.…”