Browne, Duncan L’s team published research in Journal of the American Chemical Society in 2009-06-10 | 1002334-12-4

Journal of the American Chemical Society published new progress about [3+2] Cycloaddition reaction. 1002334-12-4 belongs to class pyrazoles-derivatives, and the molecular formula is C15H19BN2O2, Recommanded Product: 1-Phenyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole.

Browne, Duncan L.; Vivat, Jerome F.; Plant, Andrew; Gomez-Bengoa, Enrique; Harrity, Joseph P. A. published the artcile< Investigation of the scope and regiochemistry of alkynylboronate cycloadditions with sydnones>, Recommanded Product: 1-Phenyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole, the main research area is sydnone alkynylboronate cycloaddition regioselective pyrazole boronate preparation; pyrazole boronate dioxaborolanyl preparation regioselective cycloaddition sydnone alkyne alkynylboronate; boronate pyrazolyl substituted preparation cycloaddition alkynylboronate; transition state structure regioselectivity cycloaddition alkynylboronate sydnone preparation pyrazolylboronate; potential energy surface regioselectivity cycloaddition alkynylboronate sydnone preparation pyrazolylboronate; optimized geometry sydnone alkynylboronate cycloaddition intermediate pyrazole transition state.

Di-, tri-, and tetrasubstituted 3- and 4-pyrazolylboronates were prepared by a convenient and highly regioselective procedure comprising cycloaddition of alkynylboronates to sydnones. Addition of 3-R1-4-R2-5-oxy-1,2,3-oxadiazolium with 2-alkynyl-4,4,5,5-tetramethyl-1,3,2-dioxaborolanes R3CCB(OCMe2)2 in 1,2-dichlorobenzene at 180° gave 1-R1-3-R3-4-X-5-R2-1H-pyrazoles (20a-30a; X = 4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl; R1 = Ph, Me, 4-NO2C6H4; R2 = Ph, Me, iPr; R3 = Ph, Me3Si); the corresponding regioisomers, 1-R1-4-R3-3-X-5-R2-1H-pyrazoles, were formed in less than 2% amounts However, regioselectivity (a:b) of the reaction of 3-Ph-5-oxy-1,2,3-oxadiazolium with R4CCB(OCMe2)2 giving 1-R1-3-R4-4-X- and 1-R1-4-R4-3-X-1H-pyrazoles (8a-13a, 8b-13b, resp., R1 = Ph, Me, PhCH2, R4 = H, Bu, Me3Si) was lower (1:7, 5:2 and 2:1, resp.). The origins of an observed regiochem. divergence in the reactions of terminal alkynylboronates with their more substituted analogs have been studied by DFT methods.

Journal of the American Chemical Society published new progress about [3+2] Cycloaddition reaction. 1002334-12-4 belongs to class pyrazoles-derivatives, and the molecular formula is C15H19BN2O2, Recommanded Product: 1-Phenyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole.

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics