Acyloxy derivatives of trivalent phosphorus in amidoalkylation of hydrophosphoryl compounds
摘要:
In order to model the previously suggested mechanism of the P-C bond formation via the Arbuzov reaction, we have studied the interaction of diethylacylphosphite (prepared beforehand as well as generated in situ from tetraethylpyrophosphite) with the in situ generated acyliminium cation. Various conditions of in situ generation of acylphosphite derivatives of P(III) from hydrophosphoryl compounds and acyliminium ions from N,N'-alkylidenebiscarbamates have been investigated: solvent nature, acid catalyst, and the reagents mixing order). The results obtained have confirmed the suggested mechanism of three-component reaction of amidoalkylation of hydrophosphoryl compounds with the formation of P-C bond via the Arbuzov reaction of in situ formed intermediates.
Arbuzov-type reaction of acylphosphonites and N-alkoxycarbonylimine cations generated in situ with trifluoroacetic anhydride
作者:Maxim E. Dmitriev、Valery V. Ragulin
DOI:10.1016/j.tetlet.2012.01.094
日期:2012.3
N-protected α-aminoalkylphosphinic acids by the reaction of N,N′-benzylidene- or N,N′-alkylidenebiscarbamates, trifluoroaceticanhydride and the corresponding alkylphosphonous acids in methylene chloride or toluene is described. The results obtained confirm the earlier proposed mechanism for amidoalkylation of hydrophosphorylic compounds involving an Arbuzov-type reaction step.
N-Boc-aminals as easily accessible precursors for less accessible N-Boc-imines: facile synthesis of optically active propargylamine derivatives using Mannich-type reactions
We developed a facile and practical synthesis of N-Boc-aminals, which can be used as precursors for less accessible N-Boc-imines. Aminals were obtained via simple dehydration condensation reactions of t-butyl carbamate (BocNH2) and various aldehydes in acetic anhydride, followed by filtration and washing with hexane. The obtained N-Boc-alkynylaminals could be successfully applied in enantioselective
Crafty aminals: The in situgeneration of hitherto unattainable alkynyl‐substituted N‐Boc‐protected imines was realized by the acid‐catalyzed elimination of tert‐butyl carbamate from N‐Boc aminals. A wide variety of N‐Boc imines can be generated, which can then be utilized for subsequent carbon–carbon bond‐forming reactions, such as Mannich‐type reactions.
Rh-Catalyzed, Regioselective, C–H Bond Functionalization: Access to Quinoline-Branched Amines and Dimers
作者:M. Damoder Reddy、Frank R. Fronczek、E. Blake Watkins
DOI:10.1021/acs.orglett.6b02848
日期:2016.11.4
Rh-catalyzed, chelation-induced, C-5 regioselectiveC–Hfunctionalization of 8-amidoquinolines with a range of N-Boc aminals is reported for the first time. The addition of in situ generated imines to C(sp2)–H bonds afforded branched amines in good to excellent yields. Moreover, this transformation features good functional group compatibility, broad substrate scope, and mild reaction conditions and