Palladium-Catalyzed Highly Regioselective [3 + 2] Cycloaddition Reactions of Alkylidenecyclopropa[<i>b</i>]naphthalenes with Alkenes or Alkynes: An Efficient Synthesis of 1(3)-Alkylidene-2,3-dihydro-1<i>H</i>-benzo[<i>f</i>]indenes and 1-Alkylidene-1<i>H</i>-benzo[<i>f</i>]indenes

The first palladium-catalyzed highly regioselective [3 + 2] cycloaddition reactions of alkylidenecyclopropa[b]naphthalenes 1 with alkenes or alkynes is presented, providing an efficient method for the synthesis of 1(3)-alkylidene-2,3-dihydro-1H-benzo[f]indenes or 1-alkylidene-1H-benzo[f]indenes under mild conditions

Facile and Effective Copper-Mediated Cyclization Reaction of Cyclopropylideneacetic Acids (or Esters) and Cyclopropylideneacetonitriles

The full details of the copper-mediated cyclization reaction of cyclopropylideneacetic acids (or esters) and cyclopropylidenenitriles, the synthetic application of this reaction, and the study of the reaction mechanism are reported

Palladium-Catalyzed Highly Regioselective [3 + 2] Cycloaddition Reactions of Alkylidenecyclopropa[<i>b</i>]naphthalenes with Alkenes or Alkynes: An Efficient Synthesis of 1(3)-Alkylidene-2,3-dihydro-1<i>H</i>-benzo[<i>f</i>]indenes and 1-Alkylidene-1<i>H</i>-benzo[<i>f</i>]indenes

The first palladium-catalyzed highly regioselective [3 + 2] cycloaddition reactions of alkylidenecyclopropa[b]naphthalenes 1 with alkenes or alkynes is presented, providing an efficient method for the synthesis of 1(3)-alkylidene-2,3-dihydro-1H-benzo[f]indenes or 1-alkylidene-1H-benzo[f]indenes under mild conditions

First Tandem Free-Radical Cyclization Reaction of Alkylenecyclopropanes: A Novel and Efficient Method for the Preparation of 2-(3,4-Dihydronaphthalen-2-yl)malonic Acid Diethyl Esters

Alkylidenecyclopropanes undergo Mn(OAc)3-mediated addition with malonate, leading to dihydronaphthalene derivatives in moderate yields

Presentation_1_The Application of a Meiocyte-Specific CRISPR/Cas9 (MSC) System and a Suicide-MSC System in Generating Inheritable and Stable Mutations in Arabidopsis.pdf

<p>The CRISPR/Cas9 system has been widely used for generating targeted mutations in various species. In Arabidopsis, it largely relies on the edited cells where the Cas9 protein performs its activity to obtain heritable and stable mutated lines. Here, we designed an improved CRISPR/Cas9 system, named as the MSC (meiocyte-specific CRISPR/Cas9) system, in which the Cas9 expression is driven by an experimentally approved meiocyte-specific promoter (AtDMC1 promoter). Two endogenous genes, including vegetative gene AtDET2 and reproductive gene AtDMC1, were targeted. We obtained heterozygous T1 plants for targeted genes with high efficiency (64%). In the T2 generation, the homozygous plants were abundant with high efficiency (37%). Analysis of Sanger sequencing results of T2 generation revealed that heritable gene mutations were high (52%). Moreover, we showed that the MSC system could sufficiently delete a middle size DNA fragment (∼500 bp) between two cleavage sites with a high rate (64.15%) in the T1 plants, providing direct evidence for making complete knock-out or certain domain-depletion mutations. In addition, we further made a suicide-MSC system, which can edit the targeted endogenous gene and the exogenous Cas9 gene simultaneously, not only successfully avoiding the further destroy of alleles brought in by molecular complementary or genic allelic test, but also maintaining the stable mutated alleles for functional studies. In short, the two systems provide new approaches to generate mutations for gene functional studies.</p

Image_1_Stratigraphic evolution and drowning steps of a submerged isolated carbonate platform in the northern South China Sea.tif

Drowned carbonate platforms on passive margins present a paradox, because their great growth potential exceeds the typical rates of passive margin subsidence and any relative sea-level rise driven by long-term processes in the geologic record. In this study, manned submersible observations, sampling, and high-resolution acoustic data were used to investigate a drowned isolated carbonate platform cropping out at a water depth of 536–800 m in the northern South China Sea. Based on the results, the Early Miocene strata of the platform are grouped into three units (AU1, AU2, and AU3) that formed on the fault-created topography. The fault-created topography served as a template for the onset of the carbonate platform deposition and as a pedestal for the localization of backstepped platforms in response to accommodation space variations, primarily driven by rapid subsidence and eustatic rises during the Early Miocene. The Middle Miocene strata of the platform are grouped into four units (AU4, PU1, PU2, and PU3), exhibiting a general switch from dominantly aggrading to dominantly prograding platform margins, in tandem with the cessation of faulting. The biostratigraphy and established seismic–stratigraphic correlations indicate that the carbonate platform was submerged during the late Middle Miocene. The banktop consists of a heterozoan carbonate factory dominated by large benthic foraminifera and coralline algae. This facies was deposited during a time interval when summer monsoon-induced upwelling triggered heterozoan factory turnover in other carbonate platforms in the region, such as at well XK-1 (Xuande Platform). The asymmetric backstepping of the platform margins demonstrates that summer monsoon-driven currents influenced the platform drowning. Therefore, summer monsoon-induced upwelling was a major factor influencing platform drowning during the late Middle Miocene. Platform growth did not persist due to the high subsidence rate throughout the Late Miocene. This study provides new insights into the drowning mechanism of a Miocene carbonate platform in the northern South China Sea and a new seismic analog for other ancient, isolated platforms worldwide.</p

Biodegradable Polysarcosine with Inserted Alanine Residues: Synthesis and Enzymolysis

Polysarcosine (PSar), a water-soluble polypeptoid, is gifted with biodegradability via the random ring-opening copolymerization of sarcosine- and alanine-N-thiocarboxyanhydrides catalyzed by acetic acid in controlled manners. Kinetic investigation reveals the copolymerization behavior of the two monomers. The random copolymers, named PaS, with high molecular weights between 5.3 and 43.6 kg/mol and tunable Ala molar fractions varying from 6 to 43% can be degraded by porcine pancreatic elastase within 50 days under mild conditions (pH = 8.0 at 37 °C). Both the biodegradation rate and water solubility of PaS depend on the content of Ala residues. PaS with Ala fractions below 43% are soluble in water, while the one with 43% Ala self-assembles in water into nanoparticles. Moreover, PaS are noncytotoxic at the concentration of 5 mg/mL. The biodegradability and biocompatibility endow the Ala-containing PSar with the potential to replace poly­(ethylene glycol) as a protective shield in drug-delivery

Manganese(III) Acetate-Mediated Cyclization of Diarylmethylenecyclopropa[<i>b</i>]naphthalenes: A Method for the Synthesis of 1,2-Benzanthracene Derivatives

The manganese­(III) acetate-mediated free radical cyclization of diarylmethylenecyclopropa­[b]­naphthalenes with nucleophiles such as carboxylic acid and sulfonic acid provides an efficient method for the synthesis of 1,2-benzanthracenes in moderate to good yields under mild conditions. In addition, after several steps of simple and routine operations, the obtained 1,2-benzanthracenes bearing an acetoxy group could be easily converted to structurally more sophisticated 1,2-benzanthracene derivatives, which are not easily accessible yet potentially useful candidates for materials science

Image_2_Stratigraphic evolution and drowning steps of a submerged isolated carbonate platform in the northern South China Sea.tif

Drowned carbonate platforms on passive margins present a paradox, because their great growth potential exceeds the typical rates of passive margin subsidence and any relative sea-level rise driven by long-term processes in the geologic record. In this study, manned submersible observations, sampling, and high-resolution acoustic data were used to investigate a drowned isolated carbonate platform cropping out at a water depth of 536–800 m in the northern South China Sea. Based on the results, the Early Miocene strata of the platform are grouped into three units (AU1, AU2, and AU3) that formed on the fault-created topography. The fault-created topography served as a template for the onset of the carbonate platform deposition and as a pedestal for the localization of backstepped platforms in response to accommodation space variations, primarily driven by rapid subsidence and eustatic rises during the Early Miocene. The Middle Miocene strata of the platform are grouped into four units (AU4, PU1, PU2, and PU3), exhibiting a general switch from dominantly aggrading to dominantly prograding platform margins, in tandem with the cessation of faulting. The biostratigraphy and established seismic–stratigraphic correlations indicate that the carbonate platform was submerged during the late Middle Miocene. The banktop consists of a heterozoan carbonate factory dominated by large benthic foraminifera and coralline algae. This facies was deposited during a time interval when summer monsoon-induced upwelling triggered heterozoan factory turnover in other carbonate platforms in the region, such as at well XK-1 (Xuande Platform). The asymmetric backstepping of the platform margins demonstrates that summer monsoon-driven currents influenced the platform drowning. Therefore, summer monsoon-induced upwelling was a major factor influencing platform drowning during the late Middle Miocene. Platform growth did not persist due to the high subsidence rate throughout the Late Miocene. This study provides new insights into the drowning mechanism of a Miocene carbonate platform in the northern South China Sea and a new seismic analog for other ancient, isolated platforms worldwide.</p

Manganese(III) Acetate-Mediated Cyclization of Diarylmethylenecyclopropa[<i>b</i>]naphthalenes: A Method for the Synthesis of 1,2-Benzanthracene Derivatives

The manganese­(III) acetate-mediated free radical cyclization of diarylmethylenecyclopropa­[b]­naphthalenes with nucleophiles such as carboxylic acid and sulfonic acid provides an efficient method for the synthesis of 1,2-benzanthracenes in moderate to good yields under mild conditions. In addition, after several steps of simple and routine operations, the obtained 1,2-benzanthracenes bearing an acetoxy group could be easily converted to structurally more sophisticated 1,2-benzanthracene derivatives, which are not easily accessible yet potentially useful candidates for materials science