Catalytic [2 + 2 + 2] cycloaddition with indium(iii)-activated formaldimines: a practical and selective access to hexahydropyrimidines and 1,3-diamines from alkenesElectronic supplementary information (ESI) available. CCDC 1538722 and 1554489. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c7sc02576a

• Main Authors: Zhou, Hui, Chaminda Lakmal, Hetti Handi, Baine, Jonathan M, Valle, Henry U, Xu, Xue, Cui, Xin
• Format: Article
• Language: English
• ISSN: 2041-6520; 2041-6539
• DOI: 10.1039/c7sc02576a

Catalytic [2 + 2 + 2] cycloaddition with imines has, for the first time, been developed as a practical and selective approach for direct construction of hexahydropyrimidine derivatives from various alkenes. With formaldimines as reagents and simple InCl 3 as the catalyst, this ionic [2 + 2 + 2] approach is applicable for a wide scope of alkenes and allenes with various electronic and steric properties, as well as substitution patterns. Through facile hydrolysis of the resulting hexahydropyrimidines, this catalytic process also provides a new synthetic strategy for the aminomethylamination of alkenes and allenes to practically access 1,3-diamine derivatives. Catalytic [2 + 2 + 2] cycloaddition with three double bond systems has been developed for construction of hexahydropyrimidine and 1,3-diamine derivatives.