Diastereoselective 1,3-nitrooxygenation of bicyclo[1.1.0]butanes.

Cyclobutanes are strained carbocycles found in many drugs and natural products. Herein, we report a diastereoselective 1,3-nitrooxygenation of bicyclo[1.1.0]butanes with -butylnitrite and TEMPO to access 1,1,3-trisubstituted cyclobutanes. Various bicyclo[1.1.0]butanes effectively participated in the radical reaction yielding the substituted cyclobutane scaffolds with excellent yields and diastereoselectivity. The reaction is catalyst-free, easy to perform, and scalable and can be conducted in open air. Products obtained serve as substrates for the synthesis of 1,1,3,3-tetrasubstituted cyclobutanes with good yields and diastereoselectivity.