No abstract

International audienceThe catalytic activity of four aminocarbonyl group containing 'boomerang'-type ring-closing metathesis catalysts have been studied for ten-membered lactone and compared well with the Grubbs I and II as well as the Hoveyda-Grubbs catalysts. The activity was found to be superior to the above three ring-closing metathesis catalysts and suggesting novel stereoselective total syntheses of herbarumin I and stagonolide A

C omm u n fi c a ft fi o n P o fl fl fi n a ft fi o n e c o fl o g y a n d f r u fi ft fi n g b e h a v fi o r o f P a v e ft ft a fi n d fi c a L . ( R u b fi a c e a e ) , a k e y s ft o n e s h r u b s p e c fi e s fi n ft h e s o u ft h e r n E a s ft e r n G h a ft s f o r e s ft , A n d h r a P r a d e s h , I n d fi a A . J . S o fl om o n R a j u , M . M a fl fl fi k a r j u n a R a o , K . V e n k a ft a R am a n a , C . P r a s a d a R a o & M . S u fl a k s h a n a

We report on the ultrafast (femtosecond) laser ablation of monocrystalline Si (100), polycrystalline Si, and Si (100) capped with a SiO2 layer. The target material was ablated using femtosecond laser pulses (~50 fs duration, 1 kHz repetition rate, and 800 nm wavelength) with an input energy of ~100 μJ in acetone medium to fabricate Si Nanoparticles (NPs). The average size of NPs produced by Si (100) was found to be less than that of the particles produced by poly Si. Ablation of Si caped with SiO2 resulted in bigger Si NPs together with a low concentration of SiO2 NPs. NPs were found to be of polycrystalline in all three cases irrespective of the initial phase.

No abstract

Catalytic Activity Studies of Aminocarbonyl Group Containing Hoveyda--Grubbs-Type Complexes for the Syntheses of Herbarumin I (IV) and Stagonolide A (V).-It is demonstrated that the "boomerang"-type catalysts are more efficient than the standard types for the preparation of key intermediate (III). -(MOHAPATRA*, D. K.; SOMAIAH, R.; RAO, M. M.; CAIJO, F.; MAUDUIT, M.; YADAV*, J. S.; Synlett

Information on pollination ecology and seed dispersal aspects is essential to understand sexual reproduction in Lagascea mollis Cav. The study was aimed at providing details of pollen presentation system, pollination syndrome, pollinators and seed dispersal mode for L. mollis based mostly on field study. Paper chromatography technique was used for recording sugar and amino acid types in the nectar, since they are important to evaluate the pollination syndrome. The study indicated that L. mollis flowers during August-November. The plant produces synflorescences consisting of several capitula. Each capitulum produces a single disc floret. The plant is protandrous, temporally dioecious and exhibits secondary pollen presentation using brush mechanism to prevent autonomous selfing. The floral characteristics such as having synflorescence, narrow tubular corolla, production of sucrose-rich nectar with essential and non-essential amino acids and pollen charactersistics such as having spherical shape, tri-colpate apertures and strongly spinulose exine suggested that the plant is adapted for insect pollination. The plant is principally psychophilous. Other insects also visited the florets opportunistically and acted as supplementary pollinators. Further, thrips used this plant as breeding and feeding sites; their effect mostly geitonogamy. The fruit is an achene, anemochorous and also anthropochorous. Regeneration occurred from seeds and perennial root stock during rainy season.

Concise Total Synthesis of Botryolide B. -(MOHAPATRA*, D. K.; UMAMAHESHWAR, G.; RAO, M. M.; UMADEVI, D.; YADAV, J. S.; RSC Adv. 4 (2014) 16, 8335-8340, http://dx.doi.org/10.1039/c3ra44478c ; Nat. Prod. Chem. Div., Indian Inst. Chem. Technol., Hyderabad 500 007, India; Eng.) -M. Tismer 46-222