A novel chiral amide-phosphine bifunctional catalyst was developed and successfully catalyzed the asymmetric intermolecular vinylogous 3+2 annulations of MBH carbonates with benzofulvenes, affording cyclopentene spiroindenes with excellent regioselectivity and stereoselectivity (up to >20:1 dr and >99% ee), which are widely present in natural products and chiral catalysts.
Si et al. (Fri,) studied this question.