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Search for "tetrazoles" in Full Text gives 31 result(s) in Beilstein Journal of Organic Chemistry.
3-Pyridylnitrene, 2- and 4-pyrimidinylcarbenes, 3-quinolylnitrenes, and 4-quinazolinylcarbenes. Interconversion, ring expansion to diazacycloheptatetraenes, ring opening to nitrile ylides, and ring contraction to cyanopyrroles and cyanoindoles
Beilstein J. Org. Chem. 2013, 9, 743–753, doi:10.3762/bjoc.9.84
- tetrazoles 23 and 24 are collected in Table 1. The formation of different mixtures of the three cyanodimethylpyrroles 25–27 depending on the conditions can be explained in terms of chemical activation. The formation of (hetero)arylcarbenes and their rearrangement to (hetero)arylnitrenes and cyanopyrroles are
- is required for this, whereas 400 °C suffices in the FVT of the tetrazoles (Table 1). Following the analysis of the ring contraction in 3-pyridylnitrene (10) by ring expansion and ring opening to a nitrile ylide (Scheme 4 and Figure 1), we can interpret the reactions in terms of ring expansion of the
Some aspects of radical chemistry in the assembly of complex molecular architectures
Beilstein J. Org. Chem. 2013, 9, 557–576, doi:10.3762/bjoc.9.61
- (nitrile, ketones, esters, pyridines, tetrazoles, etc.) are particularly suitable. Benzyl radicals are not reactive enough towards unactivated alkenes; they tend to accumulate in the medium and ultimately dimerise. (b) The addition product, 30, being itself a xanthate, allows the implementation of a second
A quantitative approach to nucleophilic organocatalysis
Beilstein J. Org. Chem. 2012, 8, 1458–1478, doi:10.3762/bjoc.8.166
- adducts could only be isolated when the reaction mixtures containing 16 (for R2 = H) were worked up with dry K2CO3. Aqueous workup led to regeneration of the reactants. Vicario’s report that imidazoles, in contrast to triazoles and tetrazoles, do not readily undergo iminium activated additions to α,β
Synthesis of chiral sulfoximine-based thioureas and their application in asymmetric organocatalysis
Beilstein J. Org. Chem. 2012, 8, 1443–1451, doi:10.3762/bjoc.8.164
- . They involve both metal catalysis [64][65] as well as organocatalysis. In the latter field, chiral phosphoric acids [66][67], bicyclic diamines [68], bifunctional thioureas [69], proline ester salts [70], pyrrolidinyl tetrazoles [71], and a quinine-derived amine [72] were reported to catalyze the
Continuous-flow enantioselective α-aminoxylation of aldehydes catalyzed by a polystyrene-immobilized hydroxyproline
Beilstein J. Org. Chem. 2011, 7, 1486–1493, doi:10.3762/bjoc.7.172
- ], binaphthyl-derived amines [22][23][24], pyrrolidin-2-yl-tetrazoles [25][26][27][28], thiaproline [29], 2-aminomethylpyrrolidine sulfonamide [30] and sulfonylcarboxamide [31], have been successfully used to promote the reaction. As a matter of fact, the rapid development of the methodology for the asymmetric
Unusual behavior in the reactivity of 5-substituted-1H-tetrazoles in a resistively heated microreactor
Beilstein J. Org. Chem. 2011, 7, 503–517, doi:10.3762/bjoc.7.59
- , followed by translation to high-temperature/high-pressure scalable continuous flow processes (“microwave-to-flow” paradigm) [26][27][28]. A recent example involves the synthesis of 5-substituted-1H-tetrazoles via an azide–nitrile cycloaddition pathway, using sodium azide (NaN3) as an inexpensive azide
- formed from HN3 and Fe metal at temperatures around 100 °C which represents a serious safety hazard [38]. On the other hand, it has been reported that the decomposition of tetrazoles can be catalyzed by a whole range of metals. For example, Cu powder was found to lower the decomposition temperature of
- environment [41], in combination with the use of a flow reactor that employed a standard Al heating block as a coil heater [25]. Using this set-up, a general and scalable method for the continuous flow synthesis of 5-substituted-1H-tetrazoles via the addition of HN3 to organic nitriles was developed [25]. For
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