Cyclizations of cyclic and acyclic carbonates

August 14, 2024

• Title:       

  Cyclizations of cyclic and acyclic carbonates

• Image Source:

  Palladium-catalyzed asymmetric synthesis of 2-alkynyl oxacycles

• Mark:

  Table 2

• Associated context:

  We were thus delighted to find that carbonates 6d and 6e gave the THPs 11a and 11b with excellent yield and ee (Table 2, entries 7 and 8), despite the need for a higher temperature (1008C) and additional boric acid. This selectivity was maintained for the disubstituted substrates 6 f and 6g, which afforded the corresponding 2,6-  disubstituted THPs 11c and 11d with high selectivity for both isomers (Table 2, entries 9 and 10).