(E)-ent-15-Trityloxy-8,13-labdadiene

An unprecedented family of three- and five-membered substituted anionic derivatives of parent pnictogenylboranes is herein reported. Reacting various combinations of the pnictogenylboranes H2 E'-BH2 -NMe3 (E'=P, As) with pnictogen-based nucleophiles MER1R2 (E=P, As; R1=H, R2=t Bu; R1=R2=Ph; M=Na, K) allows for the isolation of the unsymmetrical products [Na(18-crown-6)][H2 E'-BH2 -EHt Bu] (3: E=E'=P; 4: E=E'=As; 5: E=As, E'=P) and [M(C)][H2 E'-BH2 -EPh2 ] (7: E=E'=P, M=Na, C=18-crown-6; 8: E=E'=As; M=K, C=[2.2.2]cryptand; 9: E=P, E'=As, M=Na, C=[2.2.2]cryptand; 10: E=As, E'=P, M=K, C=[2.2.2]cryptand). [Na(18-crown-6)][H2 As-BH2 -t BuPH-BH3 ] (6) is only accessible by a different pathway, using t BuPH2 , BH3 ⋅ SMe2 and NaNH2 as starting materials. Additionally, the synthesis of symmetrical diphenyl-substituted compounds [M(18-crown-6)][Ph2 E-BH2 -EPh2 ] (11: E=P, M=Na; 12: E=As, M=K) is reported which can be regarded as isostructural inorganic, negatively charged analogs of dppm (1,1-bis(diphenylphosphino)methane) and dpam (1,1-bis(diphenylarsino)methane). Furthermore, an elongation of the pnictogen boron backbone in compounds 3, 7 and 9' (similar compound to 9, stabilized however by 18-crown-6), is attainable by reacting them with the pnictogenylboranes H2 E'-BH2 -NMe3 leading to corresponding five-membered chain-like compounds [Na(18-crown-6)][H2 E-BH2 -R1R2P-BH2 -E'H2 ] (E=E'=P, R1=H, R2=t Bu (13); E=E'=P, R1=R2=Ph (14); E=E'=As, R1=R2=Ph (15); E=P, E'=As, R1=R2=Ph (16)). Finally, the thermodynamics of the reaction pathways were evaluated by quantum chemical computations.

A new strategy for the synthesis of conjugated (E,E)-dienones and (E,E)-dienals via a palladium-catalyzed aerobic γ,δ-dehydrogenation of enones and enals has been developed. The method can be employed in the direct and efficient synthesis of various (E,E)-dienones and (E,E)-dienals, including non-substituted α-, β-, and γ- and/or δ-substituted (E,E)-dienones and (E,E)-dienals. The protocol is featured by the ready accessibility and elaboration of the starting materials, good functional group compatibility, and mild reaction conditions. Furthermore, the reaction is of complete E,E-stereoselectivity and uses molecular oxygen as the sole clean oxidant.

Introduction: Given the lack of regulation on marketing of electronic cigarettes (e-cigarettes) in the United States and the increasing exchange of e-cigarette-related information online, it is critical to understand how e-cigarette companies market e-cigarettes and how the public engages with e-cigarette information. Methods: Results are from a systematic review of peer-reviewed literature on e-cigarettes via a PubMed search through June 1, 2017. Search terms included: "e-cigarette*" or "electronic cigarette" or "electronic cigarettes" or "electronic nicotine delivery" or "vape" or "vaping." Experimental studies, quasi-experimental studies, observational studies, qualitative studies, and mixed methods studies providing empirical findings on e-cigarette marketing and communication (ie, nonmarketing communication in the public) were included. Results: One hundred twenty-four publications on e-cigarette marketing and communication were identified. They covered topics including e-cigarette advertisement claims/promotions and exposure/receptivity, the effect of e-cigarette advertisements on e-cigarette and cigarette use, public engagement with e-cigarette information, and the public's portrayal of e-cigarettes. Studies show increases in e-cigarette marketing expenditures and online engagement through social media over time, that e-cigarettes are often framed as an alternative to combustible cigarettes, and that e-cigarette advertisement exposure may be associated with e-cigarette trial in adolescents and young adults. Discussion: Few studies examine the effects of e-cigarette marketing on perceptions and e-cigarette and cigarette use. Evidence suggests that exposure to e-cigarette advertisements affects perceptions and trial of e-cigarettes, but there is no evidence that exposure affects cigarette use. No studies examined how exposure to e-cigarette communication, particularly misleading or inaccurate information, impacts e-cigarette, and tobacco use behaviors. Implications: The present article provides a comprehensive review of e-cigarette marketing and how the public engages with e-cigarette information. Studies suggest an association between exposure to e-cigarette marketing and lower harm perceptions of e-cigarettes, intention to use e-cigarettes, and e-cigarette trial, highlighting the need to for advertising regulations that support public health goals. Findings from this review also present the methodological limitations of the existing research (primarily due to cross-sectional and correlational analyses) and underscore the need for timely, rigorous research to provide an accurate understanding of e-cigarette marketing and communication and its impact on e-cigarette and tobacco product use.