3‐diynes is described. Key for the success of this novel transformation is the utilization of an advanced palladium catalyst system with the specific ligand Neolephos. The synthetic value of this general approach to synthetically useful α‐alkynyl‐α, β‐unsaturated amides is showcased by diversification of several structurally complex molecules and marketed drugs. Control experiments and density‐functional
Purpose To study the changes in visual and tear film function following superficial excimer laser phototherapeutic keratectomy in patients with mid-stromal corneal scars. Methods Fourteen eyes of 14 patients with mid-stromal corneal scars seen at the Department of Ophthalmology at Kobe Kaisei Hospital underwent superficial phototherapeutic keratectomy (PTK). The subjects underwent routine ophthalmic examinations, corneal sensitivity measurements, tear film break-up time (BUT), Schirmer test and tear film lipid layer interferometry. Thirty eyes of 15 normal control subjects were also studied. The patients and the control subjects were compared for pre-PTK tear function parameters and tear film lipid layer interferometry grade. The alterations in these parameters within 6 months following PTK were also determined. Results Visual improvement was achieved in 12 eyes (86%). A hyperopic shift was observed in all eyes. The average pre-PTK corneal sensitivity and tear film BUT were lower in patients compared with control subjects before PTK. Tear film lipid layer interferometry grades were also higher in the patients than the controls before PTK. All these parameters improved gradually and significantly after PTK. Schirmer test results did not show any significant alterations after PTK. Conclusion We conclude that PTK is an effective means of treating corneal scars and attaining visual improvement, even in cases with deeper corneal involvement, and may obviate the need for corneal transplantation. Simultaneous improvements in corneal sensitivity and tear film stability suggest favourable effects of PTK on the ocular surface.
The reaction of ethynylstibanes (1a–g) with vinyl halides or triflate in the presence of a palladium catalyst led to the formation of cross-coupling products (5a–g, 10–12) in good to moderate yield, along with homo-coupling products (6a–g). A similar reaction of ethynyldiphenylstibane (1a) with aryl iodides (13a–i) also gave cross-coupling products (14a–i), although the yields were relatively low.
Cobalt-catalyzed cyclization of benzamides with alkynes: a facile route to isoquinolones with hydrogen evolution
作者:Ramasamy Manoharan、Masilamani Jeganmohan
DOI:10.1039/c8ob01924j
日期:——
benzamides with alkynes assisted by an 8-aminoquinoline ligand in the presence of Co(OAc)2·4H2O and pivalicacid under an air atmosphere provided isoquinolone derivatives in good to excellent yields. In this reaction, the active Co(III) species is regenerated by the reaction of Co(I) species with pivalicacid under an air atmosphere with hydrogen evolution. The proposed mechanism was supported by competition
Regioselective palladium-catalyzed cross-coupling reactions in the synthesis of novel 2,3-disubstituted thiophene derivatives
作者:Raquel Pereira、Beatriz Iglesias、Angel R de Lera
DOI:10.1016/s0040-4020(01)00764-5
日期:2001.9
A reactivity optimization study of the palladium-catalyzed cross-coupling reactions of 2,3-dibromothiophene and organometallicreagents has been conducted. Regioselectivecoupling at the C2 position, accomplished most notably by Suzuki coupling, was combined with a Stille reaction at C3 using Fu's modification, to afford the 2,3-disubstituted thiophene derivatives.