Department of Chemistry, Rutgers University, 73 Warren Street, Newark, New Jersey 07102, United States.
Department of Chemistry, Opole University, 48 Oleska Street, Opole 45-052, Poland.
J Org Chem. 2020 Apr 17;85(8):5475-5485. doi: 10.1021/acs.joc.0c00227. Epub 2020 Apr 6.
-Acyl-glutarimides have emerged as the most reactive precursors for N-C(O) bond cross-coupling reactions to date, wherein the reactivity is driven by ground-state destabilization of the amide bond. Herein, we report a full study on the effect of a glutarimide ring on the structures, electronic properties, and reactivity of fully perpendicular -acyl-glutarimide amides. Most notably, this report demonstrates the generality of deploying -acyl-glutarimides to achieve full twist of the acyclic amide bond, and results in the discovery of -acyl-glutarimide amide with an almost perfect twist value, τ = 89.1°. X-ray structures of five new -acyl-glutarimides are reported. Reactivity studies in the Suzuki-Miyaura cross-coupling and transamidation reactions provide insight into the reactivity of -acyl-glutarimides in metal-catalyzed and transition-metal-free reactions. The effect of distortion, structures, and rotational barriers around the N-C(O) axis is discussed. The ability to achieve full distortion of the amide bond significantly expands the range of reagents available for N-C(O) cross-coupling reactions.
酰基戊二酰亚胺是目前最具反应活性的 N-C(O) 键交叉偶联反应前体，其反应活性由酰胺键的基态去稳定化驱动。在此，我们全面研究了戊二酰亚胺环对全垂直酰基戊二酰亚胺酰胺结构、电子性质和反应性的影响。值得注意的是，该报告证明了利用酰基戊二酰亚胺来实现非环酰胺键完全扭曲的通用性，从而发现了扭曲值几乎为完美的酰基戊二酰亚胺酰胺，τ = 89.1°。报道了五个新的酰基戊二酰亚胺的 X 射线结构。在铃木-宫浦交叉偶联和转酰胺反应中的反应性研究为酰基戊二酰亚胺在金属催化和无过渡金属反应中的反应性提供了深入的了解。讨论了扭曲、结构和 N-C(O) 轴周围的旋转势垒的影响。酰胺键完全扭曲的能力显著扩展了用于 N-C(O) 交叉偶联反应的试剂范围。
