Copper(I)-catalyzed intramolecular asymmetric [2 + 2] photocycloaddition. Synthesis of both enantiomers of cyclobutane derivatives.
[reaction: see text] A simple approach for asymmetric induction in Cu(I)-catalyzed [2 + 2] photocycloaddition, where asymmetric catalysts or chiral auxiliaries were inefficient, has been developed using the concept of chirality transfer from the readily available 2, 3-di-O-cyclohexylidine-(R)-(+)-glyceraldehyde. An anion-induced cleavage of the tetrahydrofuran ring of the resulting oxa-bicyclo[3.2.0]heptanes led to a convenient access to the synthetically useful cis-1,2-disubstituted cyclobutanes in enantiomerically pure form.
Sarkar
Niladri
N
Department of Organic Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India.
Nayek
Abhijit
A
Ghosh
Subrata
S
D002384:Catalysis; D003300:Copper / Q000737:chemistry*; D003500:Cyclization; D003503:Cyclobutanes / Q000138:chemical synthesis* / Q000737:chemistry; D008968:Molecular Conformation; D010777:Photochemistry; D013237:Stereoisomerism
D003503:Cyclobutanes; D003300:Copper