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1. RCCI WITH HIGH REACTIVITY S8-ULSD BLEND AND LOW REACTIVITY N-BUTANOL

   https://doi.org/https://doi.org/10.1115/ICEF2020-3010  

   Valentin Soloiu, Cesar E. (November 2020, ASME ICEF 2020)

   ASME ICEF (Ed.)

   fuel blend consisting of 10% S8 by mass (a Fischer-Tropsch synthetic kerosene), and 90% ULSD (Ultra Low Sulfur Diesel) was investigated for their combustion characteristics and impact on emissions during RCCI (Reactivity Controlled Compression Ignition) combustion in a single cylinder experimental engine utilizing a 65% by mass n-butanol port fuel injection (PFI). RCCI is a dual fuel combustion strategy achieved with the introduction of a PFI fuel of the low-reactive n-butanol, and a direct injection (DI) of a high-reactivity blend (FT-BLEND) into an experimental diesel engine. The combustion analysis and emissions testing were conducted at 1500 RPM at an engine load of 5 bar IMEP (Indicated Mean Effective Pressure), and CA50 of 9° ATDC (After Top Dead Center); CDC (Conventional Diesel Combustion) and RCCI with 65Bu-35ULSD were utilized as the baseline for AHRR (Apparent Heat Release Rate), ringing and emissions comparisons. It was found during a preliminary investigation with a Constant Volume Combustion Chamber (CVCC) that the introduction of 10% by mass S8 into a mixture with 90% ULSD by mass only increased Derived Cetane Number (DCN) by 0.8, yet it was found to have a significant effect on the combustion characteristics of the fuel blend. This led to the change in injection timing necessary for maintaining 65Bu-35F-T BLEND RCCI at a CA50 of 5° ATDC (After Top Dead Center) to be shifted 3° closer to TDC, thus affecting the Ringing Intensity (RI), Pressure Rise Rate, and heat release of the blend all to decrease. CDC was conducted with a primary injection of 14ᵒ BTDC at a rail pressure of 800 bar, all RCCI testing was conducted with 65% PFI of n-butanol by mass and 35% DI, to prevent knock, with a rail pressure of 600 bar and a pilot injection of 60° BTDC for 0.35 ms. 65Bu-35ULSD RCCI was conducted with a primary injection at 6° BTDC with neat ULSD#2, the fuel 65Bu-35F-T BLEND in RCCI had a primary injection at 3° BTDC to maintain CA50 at 9° ATDC. 65Bu-35ULSD RCCI experienced a NOX and soot emissions decrease of 40.8% and 91.44% respectively in comparison to CDC. The fuel 65Bu-35F-T BLEND in RCCI exhibited an additional decrease of NOX and soot of 32.9 and 5.3%, in comparison to 65Bu-35ULSD RCCI for an overall decrease in emissions of 73.7% and 96.71% respectively. Ringing Intensity followed a similar trend with reductions in RI for 65Bu-35ULSD RCCI decreasing only by 6.2% whereas 65Bu-35F-T BLEND had a decrease in RI of 76.6%. Although emissions for both RCCI fuels experienced a decrease in NOX and soot in comparison to CDC, UHC and CO did increase as a result of RCCI. CO emissions for 65Bu-35ULSD RCCI and 65Bu-35F-T BLEND where increased from CDC by a factor of 5 and 4 respectively with UHC emissions rising from CDC by a factor of 3.4. The fuel 65Bu-35F-T BLEND had a higher combustion efficiency than 65Bu-35ULSD in RCCI at 91.2% due to lower CO emissions of the blend. 

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2. Isocyanoalkenes: Occurrence, Syntheses, and Reactivity

   https://doi.org/10.1055/a-2677-6462  

   Tian, Huan; Fleming, Fraser F (September 2025, Synthesis)

   Isocyanoalkenes are a largely underexplored subset of isocyanides whose natural occurrence, synthesis, and reactivity are elucidated in this review. The discussion begins with an overview of the biosynthesis and natural occurrence, which provides a valuable context for the synthetic approaches to these unusual π-substituted alkenes. Building on this foundation, the review explores the characteristic reactivity of isocyanoalkenes, which is shaped by the strong electron-withdrawing nature of the isocyanide group and an almost complete lack of π-conjugation. Two primary modes of reactivity are highlighted: conjugate additions – especially in systems containing additional electron-withdrawing substituents – and radical additions to the isocyanide, often followed by annulation via iminyl radical intermediates. Special attention is given to two particularly versatile isocyanoalkenes – β-dimethylaminoisocyanoacetates and β-bromoisocyanoacetates – which readily undergo nucleophilic addition–elimination–cyclization sequences to efficiently assemble nitrogen-containing heterocycles. Overall, this review underscores the synthetic potential of isocyanoalkenes and highlights their emerging value in the construction of diverse heterocyclic scaffolds. 

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3. Taming Nitrene Reactivity with Silver Catalysts

   https://doi.org/10.1055/s-0040-1707197  

   Vine, Logan E.; Zerull, Emily E.; Schomaker, Jennifer M. (December 2020, Synlett)

   null (Ed.)

   Nitrene transfer (NT) is a convenient strategy to directly transform C–H bonds into more valuable C–N bonds and exciting advances have been made to improve selectivity. Our work in silver-based NT has shown the unique ability of this metal to enable tunable chemo-, site-, and stereoselective reactions using simple N-dentate ligand scaffolds. Manipulation of the coordination environment and noncovalent interactions around the silver center furnish unprecedented catalyst control in selective NT and provide insights for further improvements in the field. 1 Introduction 1.1 Strategies for Nitrene Transfer 1.2 Brief Summary of Chemocatalyzed Nitrene Transfer 1.3 Focus of this Account 2 Challenges in Chemocatalyzed Nitrene Transfer 2.1 Reactivity Challenges 2.2 Selectivity Challenges 2.3 Chemoselective Nitrene Transfer 2.4 Site-Selective Nitrene Transfer 2.5 Enantioselective Nitrene Transfer 3 Summary and Perspective 3.1 Future Opportunities and Challenges 3.2 Conclusion 

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4. Metalated isocyanides: formation, structure, and reactivity

   https://doi.org/10.1039/D0OB01340D  

   Altundas, Bilal; Marrazzo, John-Paul R.; Fleming, Fraser F. (August 2020, Organic & Biomolecular Chemistry)

   null (Ed.)

   Metalated isocyanides are highly versatile organometallics. Central to the reactivity of metalated isocyanides is the presence of two orthogonally reactive carbons, a highly nucleophilic “carbanion” inductively stabilized by a carbene-like isocyanide carbon. The two reactivities are harnessed in the attack of metalated isocyanides on π-electrophiles where an initial nucleophilic attack leads to an electron pair that cyclizes onto the terminal isocyanide carbon in a rapid route to diverse, nitrogenous heterocycles. Harnessing the potent nucleophilicity of metalated isocyanides while preventing electrophilic attack on the terminal isocyanide carbon has largely been driven by empirical heuristics. This review provides a foundational understanding by surveying the formation, structure, and properties of metalated isocyanides. The focus on the interplay between the structure and reactivity of metalated isocyanides is anticipated to facilitate the development and deployment of these exceptional nucleophiles in complex bond constructions. 

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5. 9-Borafluorenes: Synthesis, Properties, and Reactivity

   https://doi.org/10.1021/acs.chemrev.0c01068  

   Su, Xiaojun; Bartholome, Tyler A.; Tidwell, John R.; Pujol, Alba; Yruegas, Sam; Martinez, Jesse J.; Martin, Caleb D. (April 2021, Chemical Reviews)

   null (Ed.)