Stereoelectronic Effects in Dihapto-Coordinated Complexes of TpW(NO)(PMe3) and Their Manifestation in Diels−Alder Cycloaddition of Arenes

详细信息    查看全文

• 作者：Rebecca J. Salomon ; Edward C. Lis ; Jr. ; Monica U. Kasbekar ; Kimberley C. Bassett ; William H. Myers ; Carl O. Trindle ; Michal Sabat ; W. Dean Harman
• 刊名：Organometallics
• 出版年：2009
• 出版时间：August 24, 2009
• 年：2009
• 卷：28
• 期：16
• 页码：4724-4734
• 全文大小：1041K
• 年卷期：v.28,no.16(August 24, 2009)
• ISSN：1520-6041

文摘

The addition of singly and doubly activated dienophiles to TpW(NO)(PMe₃)(5,6-η²-anisole) and TpW(NO)(PMe₃)(5,6-η²-1,3-dimethoxybenzene) to generate dihapto-coordinated [2.2.2]bicyclooctadienes and -trienes is explored. The highly functionalized bicyclic scaffolds are isolated from the metal fragment intact. Although moderate yields hinder their synthetic application, a unique stereoelectronic effect is uncovered. Coordination diastereomers of anisoles with the methoxy substituent distal to the PMe₃ ligand have faster reaction rates relative to the proximal diastereomer. DFT calculations reveal the metal fragment possesses a dipole that directs positive charge away from the PMe₃ ligand, and a polarized cycloaddition transition state is invoked to explain this observation.