An operationally simple and convenient synthesis method toward a series of diverse spiro[4.4]thiadiazole derivatives via double [3 + 2] 1,3-dipolarcycloaddition of nitrilimines generated in situ from hydrazonyl chlorides with carbon disulfide has been achieved undermild reaction conditions.
cycloaddition of nitrile imines with 3-alkenyl-oxindoles was catalyzed by a new chiral Mg(ClO4)2 complex of an N,N′-dioxide ligand. The reaction is so far the sole catalytic synthesis of spiro-pyrazoline-oxindole derivatives. A wide variety of substrates were explored to obtain good yields (up to 98%) and excellent enantioselectivities (up to 99%). This cycloaddition expands the scope of propargyl anion type 1
In this paper, a [3 + 2] cycloaddition of Baylis–Hillmanadducts and nitrilimines has been achieved under mild reaction conditions, providing a concise approach to access biologically important pyrazoline derivatives.
stereoconvergent 1,3-dipolar cycloaddition of nitrileoxides and nitrile imines with E/Z isomeric mixture of electron-deficient olefins is reported, delivering isoxazolines and pyrazolines bearing two vicinal stereogenic tertiary and trifluoromethylated quaternary carbon centers with perfect regio- and diastereoselectivities. The possibility of concerted cycloaddition/epimerization sequence under basic
C(sp2)−H allylation of racemic trisubstituted allenoates with Morita–Baylis–Hillman (MBH) carbonates to access axially chiral tetrasubstituted allenoates. Various trisubstituted allenoates and MBH carbonates were well tolerated under mild reaction conditions, providing novel chiral tetrasubstituted allenoates with adjacent axial chirality and tertiary carbon stereocenters in high yields with good to excellent