2′‐Nitro‐2′‐propen‐1′‐yl 2,2‐Dimethylpropanoate (NPP), A Multiple Coupling Reagent

Abstract

SummaryThe title compound 1 (NPP) is prepared from formaldehyde, nitromethane, and pivaloyl chloride. It is shown to be a versatile nitroallylating reagent combining with nucleophiles as different as anilines, indoles, enolates, and organolithium compounds. This is documented by ca. 40 examples (2-30). The mechanism of the reaction is discussed. Some examples of addition of two different nucleophiles to the c,-moiety of NPP are described (35-46). This demonstrates the usefulness of NPP as a multiple coupling reagent for convergent syntheses, also of products not containing nitro groups (Scheme 4 ) .

Quasienantiomers and Quasiracemates: New Tools for Identification, Analysis, Separation, and Synthesis of Enantiomers

“…More generally, the difference in ideality of phase behavior can often be used to assign absolute configuration of a molecule if a close analogue of known configuration is available because the heterofacial (quasienantiomeric) combination of molecules almost always deviates more from ideality than the homofacial combination. [10] In a related method, cocrystallization of a pair of quasienantiomers, one of known absolute configuration and the other of unknown configuration, followed by X-ray crystallographic analysis of the quasiracemate can directly yield the absolute configuration of the unknown component. Again, the method is limited since the pair of compounds must yield suitable crystals.…”

Tin, Silicon and Related Reducing Agents

“…An example is illustrated in Eq. (8) [28]. The reaction proceeds via an intermediate nitroxide radical produced by addition of the tin radical to the oxygen atom of the nitro group followed by cleavage of the carbonnitrogen bond.…”

“…PhzSiHz (4 equiv), AlBN (loo%), reflux toluene, 100 min, yield 46% (TMS)3SiH (2.2 equiv), AlBN (5%), reflux toluene, 30 min, yield 87% (28) and (29). (TMS)ZSi(H)Me is an effective reducing agent which allows the formation of the desired product to be favored because of a slower hydrogen transfer (Table I) 30) and (31).…”

Nitroaldol reaction of nitro[11C]methane to form 2‐(hydroxymethyl)‐2‐nitro[2‐11C]propane‐1,3‐diol and [11C]Tris

“…Methods that utilize the multiple adduct as a synthetic building block are also being developed. 2 Carbon-11 is a positron-emitting radionuclide that can be used for positron emission tomography (PET) research. Iodo[ 4 In contrast to the electrophilic character of 1, 2 can be used as a nucleophile by furnishing the stabilized carbanion under mild basic conditions.…”