Preparation of Optically Active <i>cis</i>-Cyclopropane Carboxylates: Cyclopropanation of α‑Silyl Stryenes with Aryldiazoacetates and Desilylation of the Resulting Silyl Cyclopropanes

Optically active <i>cis</i>-cyclopropane carboxylates are prepared via the Rh₂(<i>S</i>-PTAD)₄-catalyzed cyclopropanation of α-silyl styrenes with aryl diazoacetates followed by desilylation of the resulting silyl cyclopropane carboxylates. The conjugation of the aryl ring with CC bond and π stacking are proposed for the stereoselectivity of cyclopropanation, and configuration inversion is observed with the desilylation process

Preparation of Optically Active <i>cis</i>-Cyclopropane Carboxylates: Cyclopropanation of α‑Silyl Stryenes with Aryldiazoacetates and Desilylation of the Resulting Silyl Cyclopropanes

Optically active <i>cis</i>-cyclopropane carboxylates are prepared via the Rh₂(<i>S</i>-PTAD)₄-catalyzed cyclopropanation of α-silyl styrenes with aryl diazoacetates followed by desilylation of the resulting silyl cyclopropane carboxylates. The conjugation of the aryl ring with CC bond and π stacking are proposed for the stereoselectivity of cyclopropanation, and configuration inversion is observed with the desilylation process

Environmental data of the study sites.

<p>Climate data are the mean values over 40 years.</p><p>Environmental data of the study sites.</p

Seedling survival rates inside and outside shrub canopies of <i>C</i>. <i>stenophylla</i> in the semi-arid, arid and intensively arid zones (mean ± SE, n = 3).

<p>For variables in the same category, different letters (inside-shrub: lowercase; outside-shrub: uppercase) indicate significant differences in the means between zones (Tukey HSD tests, <i>P</i> < 0.05). Within each zone, asterisks indicate significant differences in the means between inside-shrub and outside-shrub (t-test, <i>P</i> < 0.05).</p

Average abundances of individuals arising from sexual or asexual reproduction and average total numbers of individuals for <i>C</i>. <i>stenophylla</i> shrub clusters in the semi-arid, arid and intensively arid zones (mean ± SE, n = 3).

<p>For variables in the same category, different letters (asexual reproduction individual: greek letter; sexual reproduction individual: lowercase; total number of individual: uppercase) indicate significant differences in the means between zones (Tukey HSD tests, <i>P</i> < 0.05).</p

Abundances and proportions (in parentheses) of single individuals, homologous clusters and heterologous clusters of <i>C</i>. <i>stenophylla</i> in the semi-arid, arid and intensively arid zones.

<p>Abundances and proportions (in parentheses) of single individuals, homologous clusters and heterologous clusters of <i>C</i>. <i>stenophylla</i> in the semi-arid, arid and intensively arid zones.</p