Highly Stereoselective Synthesis of (Borylmethyl)cyclopropylamines by Copper-Catalyzed Aminoboration of Methylenecyclopropanes

Abstract

A Cu-catalyzed aminoboration of 1-methylenecyclopropanes with bis(pinacolato)diboron and O-benzoyl-N,N-dialkylhydroxylamines has been developed. The Cu catalysis provides a rapid and concise access to (borylmethyl)cyclopropylamines in a highly regio- and diastereoselective manner. The products obtained can be useful building blocks for the synthesis of potential antidepressants, trans-2-arylcyclopropylamine derivatives.

[3,3]‐Sigmatropic Rearrangement of Cyclopropenylcarbinyl Cyanates: Access to Alkylidene(aminocyclopropane) Derivatives

“…[2] As a subclass of substituted cyclopropanes, aminocyclopropanes are founda sk ey structural motifs in severalb ioactive compounds, among which the monoamine oxidaseinhibitor tranylcypromine is aw ell-known representative. [3] Additional examples include the antiplatelet drugticagrelor, [4] the non-nucleosidic inhibitor of HIV-1 reverse transcriptase MIV-150, [5] the proteasome inhibitor belactosin A, [6] and the hepatitis Cv irus NS3/ 4A protease inhibitor simeprevir [7] (Figure1). Numerous methods are available fort he synthesis of aminocyclopropanes, [8] either from substrates incorporating at hreemembered ring (Curtius rearrangemento fc yclopropanecarboxylic acid or its derivatives, [8,9] addition of nitrogen nucleophiles to cyclopropanone derivatives, [10] cyclopropenes [11] or alkylidene cyclopropanes, [12] and aminationo fo rganometallic cyclopropyl species), [13] or by construction of the amino-substituted ring (by intramolecular nucleophilic substitution, [14] cyclopropanation of enamides, [15] Kulinkovich-type reactions involving amides [16] or nitriles, [17] cyclopropanation of alkenes with a-nitrocarbenoids [18] or a-aminoc arbenes/carbenoids). [19] This research field remains active as illustrated by the recent development of an ew approachr elying on the reactiono f zinc homoenolates, generated in situ from cyclopropanols, with amines.…”

Transition‐Metal‐Catalyzed Three‐Component Difunctionalizations of Alkenes

“…of up to 93:7 under similar reaction conditions. Terminal alkenes, such as 1‐methylenecyclopropanes, and internal ones, such as cyclopropenes and bicyclicalkenes (e.g., oxa‐ and azabenzonorbornadienes), all were effective after slight tuning of the reaction conditions. When the special vinylsilanes and vinylborons were used as the substrates, this reaction also took place readily under similar reaction conditions to produce the corresponding β‐boryl‐α‐aminosilanes and β‐boryl‐α‐aminoboronic acid derivatives in good‐to‐high yields.…”

Asymmetrische Synthese sekundärer und tertiärer Boronsäureester

“…Die Methode wurde später erweitert, um die Aminoborierung von bicyclischen Alkenen, [155] Methylencyclopropanen, [156] Vinylsilanen [157] und nichtaktivierten terminalen Alkenen [158] zu bewirken. Die Methode wurde später erweitert, um die Aminoborierung von bicyclischen Alkenen, [155] Methylencyclopropanen, [156] Vinylsilanen [157] und nichtaktivierten terminalen Alkenen [158] zu bewirken.…”