1484-74-8Relevant academic research and scientific papers
Enantioselective synthesis of isochromans and tetrahydroisoquinolines by C-H insertion of donor/donor carbenes
Nickerson, Leslie A.,Bergstrom, Benjamin D.,Gao, Mingchun,Shiue, Yuan-Shin,Laconsay, Croix J.,Culberson, Matthew R.,Knauss, Walker A.,Fettinger, James C.,Tantillo, Dean J.,Shaw, Jared T.
, p. 494 - 498 (2020)
Reports of C-H insertions forming six-membered rings containing heteroatoms are rare due to Stevens rearrangements occurring after nucleophilic attack on the carbene by a heteroatom. Using donor/donor carbenes and Rh2(R-PTAD)4 as a catalyst, we have synthesized a collection of isochroman substrates in good yield, with excellent diastereo- and enantioselectivity, and no rearrangement products were observed. Furthermore, we report the first synthesis of six-membered rings containing nitrogen by C-H insertion to form tetrahydroisoquinolines. In one case, a Stevens rearrangement product was isolated at elevated temperature from a carbamate-protected amine substrate and computational evidence suggests formation through a free ylide not bound to rhodium.
