Synthesis of Spiro[pyrazolin-3,3′-oxindoles] and 3‑Arylcarbonylmethyl Substituted Ylideneoxindoles by 1,3-Dipolar Cycloadditions of 3‑Ylideneoxindoles and In-Situ-Generated α‑Diazoketones

An efficient 1,3-dipolar cycloaddition of 3-ylideneoxindoles with in-situ-generated α-diazoketones to potentially biological active spiro­[pyrazolin-3,3′-oxindoles] <b>4</b> with excellent regioselectivity and diastereoselectivity and synthetically useful building block 3-arylcarbonylmethyl substituted ylideneoxindoles <b>5</b> in different conditions has been developed. This method has advantages of mild conditions, simple workup, and wide substrate scopes as well as without using any transition metal catalyst

Enantioconvergent Copper Catalysis: <i>In Situ</i> Generation of the Chiral Phosphorus Ylide and Its Wittig Reactions

The Wittig reaction, which produces alkenes from phosphorus ylides (P-ylides) and carbonyls, is one of the most powerful tools in chemical synthesis. This Nobel Prize-winning reaction is widely used in natural product synthesis, fine chemical production (i.e., medicines and agricultural agents), and polymer functionalization. Despite these great achievements, the potential of the Wittig reaction, particularly regarding the access of chiral alkene building blocks, has not been fully exploited. The main area that requires additional exploration is the development of general and practical methods to efficiently prepare chiral P-ylides. Here, we show that highly functionalized chiral P-ylides can be easily synthesized through a copper-catalyzed asymmetric propargylic alkylation reaction from phosphonium salts and racemic propargylic esters. The subsequent Wittig reactions enable the synthesis of versatile alkene building blocks, chiral α-propargylic acrylates, and α-propargylic allenoates, with a wide substrate scope and satisfactory functional group compatibility. This transformation features inexpensive transition-metal catalysts, user-friendly conditions, easily available feedstock, and high-valued products

Enantioconvergent Copper Catalysis: <i>In Situ</i> Generation of the Chiral Phosphorus Ylide and Its Wittig Reactions

The Wittig reaction, which produces alkenes from phosphorus ylides (P-ylides) and carbonyls, is one of the most powerful tools in chemical synthesis. This Nobel Prize-winning reaction is widely used in natural product synthesis, fine chemical production (i.e., medicines and agricultural agents), and polymer functionalization. Despite these great achievements, the potential of the Wittig reaction, particularly regarding the access of chiral alkene building blocks, has not been fully exploited. The main area that requires additional exploration is the development of general and practical methods to efficiently prepare chiral P-ylides. Here, we show that highly functionalized chiral P-ylides can be easily synthesized through a copper-catalyzed asymmetric propargylic alkylation reaction from phosphonium salts and racemic propargylic esters. The subsequent Wittig reactions enable the synthesis of versatile alkene building blocks, chiral α-propargylic acrylates, and α-propargylic allenoates, with a wide substrate scope and satisfactory functional group compatibility. This transformation features inexpensive transition-metal catalysts, user-friendly conditions, easily available feedstock, and high-valued products

Enantioconvergent Copper Catalysis: <i>In Situ</i> Generation of the Chiral Phosphorus Ylide and Its Wittig Reactions

The Wittig reaction, which produces alkenes from phosphorus ylides (P-ylides) and carbonyls, is one of the most powerful tools in chemical synthesis. This Nobel Prize-winning reaction is widely used in natural product synthesis, fine chemical production (i.e., medicines and agricultural agents), and polymer functionalization. Despite these great achievements, the potential of the Wittig reaction, particularly regarding the access of chiral alkene building blocks, has not been fully exploited. The main area that requires additional exploration is the development of general and practical methods to efficiently prepare chiral P-ylides. Here, we show that highly functionalized chiral P-ylides can be easily synthesized through a copper-catalyzed asymmetric propargylic alkylation reaction from phosphonium salts and racemic propargylic esters. The subsequent Wittig reactions enable the synthesis of versatile alkene building blocks, chiral α-propargylic acrylates, and α-propargylic allenoates, with a wide substrate scope and satisfactory functional group compatibility. This transformation features inexpensive transition-metal catalysts, user-friendly conditions, easily available feedstock, and high-valued products

Synthesis and Biological Activity Evaluation of Novel α‑Amino Phosphonate Derivatives Containing a Pyrimidinyl Moiety as Potential Herbicidal Agents

To find novel high-activity and low-toxicity herbicide lead compounds with novel herbicidal mode of action, series of novel α-amino phosphonate derivatives containing a pyrimidinyl moiety, <b>I</b>, <b>II</b>, <b>III</b>, and <b>IV</b>, were designed and synthesized by Lewis acid (magnesium perchlorate) catalyzed Mannich-type reaction of aldehydes, amines, and phosphites. Their structures were clearly identified by spectroscopy data (IR, ¹H NMR, ³¹P NMR, EI-MS) and elemental analyses. The bioassay [in vitro, in vivo (GH1 and GH2)] showed that most compounds <b>I</b> exhibited good herbicidal activities; for example, the activities of compounds <b>Ib</b>, <b>Ic</b>, <b>Ig</b>, <b>Ii</b>, <b>Ik</b>, and <b>Im</b> were as good as the positive control herbicides (acetochlor, atrazine, mesotrione, and glyphosate). However, their structural isomers <b>II</b> and <b>III</b> and analogues <b>IV</b> did not display any herbicidal activities in vivo, although some of them possessed selective inhibitory activity against Arabidopsis thaliana in vitro. Interestingly, it was found that compounds <b>IVs</b>, <b>IVt</b>, and <b>IVl</b> showed selective insecticidal activities against Aphis species or Plutella xylostella, respectively. Their preliminary herbicidal mode of action and structure–activity relationships were also studied