Pyrrole-Protected beta-Aminoalkylzinc Reagents for the Enantioselective Synthesis of Amino-Derivatives

Chiral beta-aminoalkylzinc halides were prepared starting from optically pure commercial beta-amino-alcohols. These amino-alcohols were converted to the correspondingN-pyrrolyl-protected alkyl iodides which undergo a zinc insertion in the presence of LiCl (THF, 25 degrees C, 10-90 min). Subsequent Negishi cross-coupling or acylation reactions with acid chlorides produced amino-derivatives with retention of chirality. Diastereoselective CBS-reductions of some preparedN-pyrrolyl-ketones provided 1,3-subsitutedN-pyrrolyl-alcohols with high diastereoselectivity. Additionally, a deprotection procedure involving an ozonolysis allowed the conversion of the pyrrole-ring into a formamide without loss of optical purity

Simple Molecules under High‐Pressure and High‐Temperature Conditions: Synthesis and Characterization of α‐ and β‐C(NH)2 with Fully sp3‐Hybridized Carbon

The elements hydrogen, carbon, and nitrogen are among the most abundant in the solar system. Still, little is known about the ternary compounds these elements can form under the high-pressure and high-temperature conditions found in the outer planets’ interiors. These materials are also of significant research interest since they are predicted to feature many desirable properties such as high thermal conductivity and hardness due to strong covalent bonding networks. In this study, the high-pressure high-temperature reaction behavior of malononitrile H2C(CN)2, dicyandiamide (H2N)2C=NCN, and melamine (C3N3)(NH2)3 was investigated in laser-heated diamond anvil cells. Two previously unknown compounds, namely α-C(NH)2 and β-C(NH)2, have been synthesized and found to have fully sp3-hybridized carbon atoms. α-C(NH)2 crystallizes in a distorted β-cristobalite structure, while β-C(NH)2 is built from previously unknown imide-bridged 2,4,6,8,9,10-hexaazaadamantane units, which form two independent interpenetrating diamond-like networks. Their stability domains and compressibility were studied, for which supporting density functional theory calculations were performed

Simple Molecules under High‐Pressure and High‐Temperature Conditions: Synthesis and Characterization of α‐ and ββ‐C(NH)2_2 with Fully sp3^3 ‐Hybridized Carbon

The elements hydrogen, carbon, and nitrogen are among the most abundant in the solar system. Still, little is known about the ternary compounds these elements can form under the high-pressure and high-temperature conditions found in the outer planets’ interiors. These materials are also of significant research interest since they are predicted to feature many desirable properties such as high thermal conductivity and hardness due to strong covalent bonding networks. In this study, the high-pressure high-temperature reaction behavior of malononitrile H$_2$C(CN)$_2$, dicyandiamide (H$_2$N)$_2$C=NCN, and melamine (C$_3$N$_3$)(NH$_2$)$_3$ was investigated in laser-heated diamond anvil cells. Two previously unknown compounds, namely $α$-C(NH)$_2$ and $β$-C(NH)$_2$, have been synthesized and found to have fully sp$^3$-hybridized carbon atoms. $α$-C(NH)$_2$ crystallizes in a distorted $β$-cristobalite structure, while $β$-C(NH)$_2$ is built from previously unknown imide-bridged 2,4,6,8,9,10-hexaazaadamantane units, which form two independent interpenetrating diamond-like networks. Their stability domains and compressibility were studied, for which supporting density functional theory calculations were performed