21906-17-2Relevant academic research and scientific papers
Direct Access to Primary Amines from Alkenes by Selective Metal-Free Hydroamination
Du, Yi-Dan,Chen, Bi-Hong,Shu, Wei
supporting information, p. 9875 - 9880 (2021/03/29)
Direct and selective synthesis of primary amines from easily available precursors is attractive yet challenging. Herein, we report the rapid synthesis of primary amines from alkenes via metal-free regioselective hydroamination at room temperature. Ammonium carbonate was used as ammonia surrogate for the first time, allowing for efficient conversion of terminal and internal alkenes into linear, α-branched, and α-tertiary primary amines under mild conditions. This method provides a straightforward and powerful approach to a wide spectrum of advanced, highly functionalized primary amines which are of particular interest in pharmaceutical chemistry and other areas.
Free radical-mediated aryl amination and its use in a convergent [3 + 2] strategy for enantioselective indoline α-amino acid synthesis
Viswanathan, Rajesh,Prabhakaran, Erode N.,Plotkin, Michael A.,Johnston, Jeffrey N.
, p. 163 - 168 (2007/10/03)
The scope of aryl radical additions to the nitrogen of azomethines is described. Aryl, trifluoromethyl alkyl, and α,β-unsaturated ketimines engage in regioselective aryl-nitrogen bond formation via 5-exo cyclizations of an aryl radical to azomethine nitrogen. Selectivity for carbon-nitrogen over carbon-carbon bond formation is generally high (>95:5) and competes only with direct aryl radical reduction by stannane (0-10%). α-Ketoimines are a promising new class of carbon radical acceptors for which no competitive aryl radical reduction is observed. The reaction conditions are pH-neutral and are therefore among the mildest methods available for amination of an aromatic ring. The ketimines examined did not suffer from competitive reduction by stannane, offering an advantage over the use of diazo and azide functional groups as nitrogen sources for carbon radicals. The free radical-mediated aryl amination was sequenced with the O'Donnell phase transfer-catalyzed enantioselective alkylation strategy of glycinyl imine to provide either enantiomer of indoline α-amino acids with high ee. These new constrained phenyl alanine derivatives are now readily available for evaluation across a variety of applications.
