Stereoselection in Intramolecular Diels–Alder Reactions of 2-Cyano-1-azadienes: Indolizidine and Quinolizidine Synthesis

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• 作者：Gidget C. Tay ; Nicholas Sizemore ; Scott D. Rychnovsky
• 刊名：Organic Letters
• 出版年：2016
• 出版时间：July 1, 2016
• 年：2016
• 卷：18
• 期：13
• 页码：3050-3053
• 全文大小：327K
• 年卷期：0
• ISSN：1523-7052

文摘

Progress toward understanding the scope and diastereoselectivity of intramolecular Diels–Alder reactions using 2-cyano-1-azadienes is described herein. The resulting cyanoenamine products are underutilized intermediates in organic synthesis. Assembly of the Diels–Alder precursors was achieved using an improved imine condensation/oxidative cyanation protocol. By this method, several highly substituted indolizidine and quinolizidine architectures were constructed. Quantum mechanical DFT calculations at the B3LYP/6-31+G(d) level of theory were performed for these cyclizations and provide insights into the origins of the observed diastereoselectivities.