The Selective Cross-Coupling of Secondary Alkyl Zinc Reagents to Five-Membered-Ring Heterocycles Using Pd-PEPPSI-IHept<sup>Cl</sup>
作者:Bruce Atwater、Nalin Chandrasoma、David Mitchell、Michael J. Rodriguez、Matthew Pompeo、Robert D. J. Froese、Michael G. Organ
DOI:10.1002/anie.201503941
日期:2015.8.10
leads to β‐hydride elimination. Whereas catalysts have been reported that provide decent selectivity for the expected (non‐rearranged) cross‐coupled product with aryl or heteroaryl oxidative‐addition partners, none have shown reliable selectivity with five‐membered‐ring heterocycles. In this report, a new, rationally designed catalyst, Pd‐PEPPSI‐IHeptCl, is demonstrated to be effective in selective
交联仲烷基中心的能力存在许多问题,包括难以进行的还原性消除,这通常导致β-氢化物消除。尽管据报道,催化剂可以为预期的(未重排)与芳基或杂芳基氧化加成伙伴交叉偶联的产物提供良好的选择性,但没有一种催化剂对五元环杂环显示出可靠的选择性。在本报告中,证明了一种经过合理设计的新型催化剂Pd-PEPPSI-IHept Cl可有效地与多种烷基呋喃,噻吩和苯并稠合衍生物(例如,吲哚,苯并呋喃),在大多数情况下,首次生产的清洁产品的迁移量极小(如果有的话)。