A Mechanism Study for Self-Cleaving Chlorotetrafluoroethylsulfinyl (-SOCF2CF2Cl)-Directed Pd(II)-Catalyzed C-H Activation.

A mechanism study for Pd(II)-catalyzed C(sp3)-H activation using a self-cleaving chlorotetrafluoroethylsulfinyl (-SOCF2CF2Cl) auxiliary as a directing group is reported. Mechanistic studies reveal that (1) the auxiliary group is crucial for C(sp3)-H activation, (2) the reaction undergoes a C(sp3)-H olefination-Michael addition-removal of the auxiliary sequence, (3) the removal of the auxiliary (SORf) is most likely the alcoholic solvolysis of the -SOCF2CF2Cl group on the N-tri-substituted sulfonamides, and (4) the C(sp3)-H cleavage is involved in the rate-determining step.

Synthesis of γ-Lactams via Pd(II)-Catalyzed C(sp3)-H Olefination Using a Self-Cleaving Polyfluoroethylsulfinyl Directing Group.

A monodentate directing group, 2-chlorotetrafluoroethylsulfinylmide (-NHSOCF2CF2Cl), for inert C(sp3)-H bond activation is reported. This directing group shows efficient ability in Pd(II)-catalyzed C(sp3)-H olefination. The desired olefination products undergo subsequent Michael addition and in situ expulsion of the auxiliary to provide the free NH γ-lactam products. Preliminary mechanistic studies reveal that the auxiliary group is crucial for C(sp3)-H activation.

Synthesis of N-H-Free 1,4-Dihydroisoquinoline-3(2H)-ones via Pd-Catalyzed C-H Olefination Using Polyfluorosulfinyl as the Auxiliary Group.

A Pd(II)-catalyzed olefination of aryl C-H bonds with a self-cleaving 2-chlorotretafluoroethylsulfinyl (-SOCF2CF2Cl) auxiliary was developed. In the reaction mixture, the olefination products underwent in situ Michael addition and the subsequent expulsion of the auxiliary to provide the N-H-free 1,4-dihydroisoquinoline-3(2H)-one products. Mechanistic studies reveal that the auxiliary group is crucial for C-H activation, and Na2CO3 and an alcoholic solvent play key roles in facilitating the cleavage of the polyfluoroalkylsulfinyl auxiliary.

Cu(II)-Catalyzed ortho-Selective Aminomethylation of Phenols.

A Cu(II)-catalyzed ortho-selective functionalization of free phenols with trifluoroborates to afford Csp2-Csp3 coupling products under mild conditions has been developed. A variety of functional groups on the phenol and the potassium aminomethyltrifluoroborate substrates were found compatible, furnishing the corresponding products in moderate to excellent yields. A single-electron transfer radical coupling mechanism involving a six-membered transition state is proposed to rationalize the high levels of ortho-selectivity in the reaction. This protocol provides straightforward access to ortho-aminomethyl-substituted phenols, unnatural amino acids and other bioactive small molecules.

5-[(2-Hy-droxy-eth-yl)(meth-yl)amino]-thio-phene-2-carbaldehyde.

In the title compound, C8H11NO2S, the aldehyde group is approximately coplanar with the thio-phene ring [maximum deviation = 0.023 (2) Å]. In the crystal, mol-ecules are linked by O-H⋯O hydrogen bonds into supra-molecular chains propagating along the a-axis direction.

Self-assembly of Terbium(III)-based metal-organic complexes with two-photon absorbing active.

Hybrid complexes based on D-π-A type dyes p-aminostyryl-pyridinum and Terbium(III) complex anion (1, 2) have been synthesized by ionic exchange reaction. Meanwhile two different alkyl-substituted amino groups were used as electron donors in organic dyes cations. The synthesized complexes were characterized by element analysis. In addition, the structural features of them were systematic studied by single crystal X-ray diffraction analysis. Their linear properties have been systematically investigated by absorption spectra and fluorescence, the results show that the energy transfer takes place from the trans-4-[4'-(N,N-diethylamino)styryl]-N-methyl pyridinium (2') cation to Tb(III). In addition, complex 2 exhibit a large two-photon absorption coefficient ß: 0.044cm/GW at 710nm.