Synthesis of Fused 3-Aminoazepinones via Trapping of a New Class of Cyclic Seven-Membered Allenamides with Furan

Abstract

Novel tricyclic tetrahydroazepinones were synthesized via an in situ Diels-Alder reaction of furan with cyclic allenamides. These reactive intermediates are the first examples of cyclic seven-membered allenamides and were prepared starting from N-(2-chloroallyl)-2-allylglycine derivatives via ring-closing metathesis followed by dehydrochlorination. The trapping of the intermediate cycloallene with furan occurred endo- and regioselectively and provided a convenient entry into new building blocks for medicinal chemistry. The diastereoselectivity of the cycloaddition was confirmed using quantum chemical computations.

Synthesis and Selective N,O‐Functionalization of Pyrazolone‐Fused 3‐Aminoazepinones

“…[6,7] At first, a Claisen rearrangement of O-allyl-N-Cbz-glycinate was used to prepare N-protected racemic Scheme 1. This was designed in analogy with our recently reported synthesis of polyheterocyclic 3-aminoazepinones via chlorinated azepinones.…”

The chemistry of the carbon-transition metal double and triple bond: Annual survey covering the year 2014

“…256) [665], homoisofagomines and analogs [666], cycloheptenes derived from two proline units [667], tuberostemospiroline and stemona lactone R [668], a cyclic α-amino acid derivative (e.g. 257) [669], tetrapetolone (through a diastereoselective RCM employing a substrate with diastereotopic vinyl groups using a chiral molybdenum complex catalyst) [670], and tricyclic IAP inhibitors (e.g.…”

The Development of Ru(II) and Fe(II) Complexes for C-H and H2 Bond Activation

“…While aromatic feedstocks are used to produce a substantial portion of petrochemicals (plastics, paints, adhesives, pharmaceuticals, cosmetics, textiles, epoxy resins, and rubber goods) 9 , the vast majority of petroleum is used to generate energy; in fact, petroleum serves as the United States' largest energy source. 10 Only about 5% of petroleum is used as feedstock for petrochemicals. 11 Given the global depletion of petroleum resources, a rational decision would be to conserve these hydrocarbons for the manufacture of petrochemical products in lieu of burning them for fuel.…”

“…. 10 Also, a metal-coordinated tris(pyrazolyl)alkane has even been observed with a naked carbanion backbone. 11 The study of poly(pyrazolyl)alkanes as ligands is not as well developed as for the poly(pyrazolyl)borate variants due in part to synthetic challenges (including moderate to low yields and multi-step isolation procedures); nevertheless, progress is being made towards greater use of this class of ligand, 3,6,9 particularly for their use in the synthesis of Cu(II)-selective membrane electrodes, 12 Re complexes for diagnostic purposes, 7 and as scaffold ligands for successful Ru(II) ethylene hydrophenylation catalysts.…”

“…[9][10][11][12][13][14][15][16][17][18] Reactions using furan can involve ring opening. For example, furan ring opening and hydrodeoxygenation of bioderived furan compounds to produce linear alkanes has been achieved in high yields and selectivity.…”