Synthetic Approach to Benzocyclobutenones Using Visible Light and a Phosphonate Auxiliary
摘要:
Reported herein is a two-step procedure to synthesize benzocyclobutenones from (o-alkylbenzoyl)-phosphonates. It consists of a visible-light-driven cyclization reaction forming phosphonate-substituted benzocyclobutenols and subsequent elimination reaction of the H-phosphonate, which assumes a key role as the recyclable auxiliary. A wide variety of functionalized benzocyclobutenones, which include those difficult to synthesize by conventional methods, are efficiently synthesized.
Regioselectivity of the Base-Induced Ring Cleavage of 1-Oxygenated Derivatives of Cyclobutabenzene
作者:Abha Gokhale、Peter Schiess
DOI:10.1002/hlca.19980810207
日期:1998.2.4
products through distal and/or proximal cleavage of the strained four-memberedring via benzyl carbanion 4 and/or aryl carbanion 5. A systematic study of this process reveals the relative stability of the two isomeric carbanions 4 and 5 as a key factor in determining the course of the ring-cleavage reaction. While benzyl carbanions 4 can be trapped with carbon electrophiles, attempts at trapping aryl