Abstract. In April-July 2008, intensive measurements were made of atmospheric composition and chemistry in Sabah, Malaysia, as part of the "Oxidant and particle photochemical processes above a South-East Asian tropical rainforCorrespondence to: C. N. Hewitt (n.hewitt@lancaster.ac.uk) est" (OP3) project. Fluxes and concentrations of trace gases and particles were made from and above the rainforest canopy at the Bukit Atur Global Atmosphere Watch station and at the nearby Sabahmas oil palm plantation, using both ground-based and airborne measurements. Here, the measurement and modelling strategies used, the characteristics of the sites and an overview of data obtained are described. Composition measurements show that the rainforest Published by Copernicus Publications on behalf of the European Geosciences Union. 170 C. N. Hewitt et al.: The OP3 project: introduction, rationale, location characteristics and tools site was not significantly impacted by anthropogenic pollution, and this is confirmed by satellite retrievals of NO 2 and HCHO. The dominant modulators of atmospheric chemistry at the rainforest site were therefore emissions of BVOCs and soil emissions of reactive nitrogen oxides. At the observed BVOC:NO x volume mixing ratio (∼100 pptv/pptv), current chemical models suggest that daytime maximum OH concentrations should be ca. 10 5 radicals cm −3 , but observed OH concentrations were an order of magnitude greater than this. We confirm, therefore, previous measurements that suggest that an unexplained source of OH must exist above tropical rainforest and we continue to interrogate the data to find explanations for this.

A cooperative Cu/Pd-catalyzed asymmetric three-component reaction of styrenes, B 2 (pin) 2 , and allyl carbonates was reported. This reaction, in the presence of chiral CuOAc/SOP and achiral Pd(dppf)Cl 2 catalysts, occurs smoothly with high enantioselectivities (up to 97% ee) . The allylboration products, which contain alkene (or diene) unite and alkylboron group, are easily functionalized. The utility of this protocol was demonstrated through the synthesis of an antipsychotic drug, (−)-preclamol.M ultifunctional and enantioenriched organoboranes are useful building blocks in the synthesis of natural products and bioactive compounds. 1 Transition metal-catalyzed asymmetric carboboration reaction is an efficient and straightforward approach to access chiral multisubstituted alkyl-or alkenylboranes. 2 For instance, Ito and co-workers developed a successful copper-catalyzed borylative cyclization to prepare optically pure β-aryl or silylated cyclopropylboronates. 3 The related asymmetric carboboration of allenes, alkynes and 1,3-enynes are also applied in the synthesis of chiral di-, tri-, and tetra-substituted alkenylboron esters by Hoveyda 1c,4 and Lin. 5 However, up to date, enantioselective carboboration of alkenes for the construction of enantioenriched and multifunctional alkylborons are less developed. Sporadic examples were reported and limited to Cu-catalyzed borylative aldol carboboration 6 and Pd-catalyzed 1,1-arylboration. 7 Very recently, Semba, Nakao 8 and Brown 9 independently reported a remarkable three-component carboboration of alkenes with bis(pinacolato)diboron (B 2 (pin) 2 ) and aryl or vinyl halides by a Cu/Pd cooperative catalysis. We envisioned using this combination catalysis 10 as a platform to develop enantioselective carboboration of simple alkenes. The proposed procedure involves two cooperative catalytic cycles (Scheme 1), a Cu-catalyzed enantioselective generation of β-borylalkylcopper 11 and a Pd-catalyzed cross-coupling transformation of this enantioenriched reagent. 1a,12 We believe that the stereospecific transmetalation of alkylcopper with XPd(L)R′ in the proposed mechanism, and the compatibility of the chiral L*Cu(I)-complex with the achiral Pd(0)-or Pd(II)-complex would be the key issues. In our previous work, 13 a stereospecific copper− tin transfer was observed in Cu(I)-catalyzed enantioselective alkene stannylboration when using chiral sulfoxide-(P-aryl)-phosphine (SOP) ligand. In this work, we found that P-alkyl sulfoxide-phosphine ligands 14 can effectively promote the aforementioned Cu−Pd transmetalation and realize a highly enantioselective allylboration of alkenes.To test the feasibility, the three-component reaction of styrene (1a), B 2 (pin) 2 , and allylic electrophiles was performed in the presence of (SOP)CuCl catalyst precursor and Pd(dppf)Cl 2 cocatalyst. After screening a series of allyl substrates with different leaving groups (e.g., halides, esters and carbonates), t-butyl allyl carbonate 2a was confirmed as the best electrophile in terms of the re...

Abstract. Ozone is an important pollutant and greenhouse gas, and tropospheric ozone variations are generally associated with both natural and anthropogenic processes. As one of the most pristine and inaccessible regions in the world,