Transition-metal-catalyzed asymmetric reactions have been a powerful tool in organic synthesis for many years. The design of chiral ligands with the right configuration is fundamental to induce high regio- and stereoselectivity to catalytic reactions and to achieve high turnover numbers and high yields. A challenge is the control of prochiral centers with similar electronic properties in a similar steric environment within the same molecule. Over the last 10 years, a range of novel rigid C-stereogenic chiral phosphine ligands has been developed and successfully applied in various types of asymmetric transformations. Many of these ligands are of a di-, tri-, or multidentate nature. The purpose of this Perspective is to highlight recent synthetic achievements (since 2010) with spiro-phosphines and other rigid phosphines and discuss some mechanistic aspects of the catalytic reactions.
Funding details: Fundação para a Ciência e a Tecnologia, FCT, UIDB/50006/2020; Funding details: European Regional Development Fund, ERDF; Funding details: Programa Operacional Temático Factores de Competitividade, POFC; Funding text 1: A.J.B. thanks FEDER (The European Fund for Regional Development) through the Operational Competitiveness Factors Program – COMPETE and the Foundation for Science and Technology (FCT, Portugal) through project UIDB/50006/2020 for financial support. ChiraTecnics thanks the University of Évora for its support and commitment over the last number of years.