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Extensive investigations of asymmetric intermolecular cyclopropanation of terminal alkenes with diazoacetates catalyzed by ruthenium porphyrin [Ru(P*)(CO)(EtOH)] (1, H2P = 5,10,15,20-tetrakis[(1S,4R,5R,8S)-1,2,3,4,5,6,7,8-octahydro-1,4:5,8-dimethanoanthracene-9-yl]porphyrin) and the application of catalyst 1 to asymmetric intramolecular cyclopropanation of allylic or homoallylic diazoacetates are described. The intermolecular cyclopropanation of styrene and its derivatives with ethyl diazoacetate afforded the corresponding cyclopropyl esters in up to 98% ee with high trans/cis ratios of up to 36 and extremely high catalyst turnovers of up to 1.1 x 10(4). Examination of the effects of temperature, diazoacetate, solvent, and substituent in the intermolecular cyclopropanation reveals that (i) both enantioselectivity and trans selectivity increase with decreasing temperature, (ii) sterically encumbered diazoacetates N2CHCO2R, such as R = Bu(t), and donor solvents, such as diethyl ether and tetrahydrofuran, are beneficial to the trans selectivity, and (iii) electron-donating para substituents on styrene accelerate the cyclopropanations, with the log(k(X)/k(H)) vs sigma(+) plot for para-substituted styrenes p-X-C6H4CH=CH2 (X = MeO, Me, Cl, CF3) exhibiting good linearity with a small negative rho(+) value of -0.44 +/- 0.09. In the case of intramolecular cyclopropanation, complex 1 promoted the decomposition of a series of allylic diazoacetates to form the cyclopropyl lactones in up to 85% ee, contributing the first efficient metalloporphyrin catalyst for an asymmetric intramolecular cyclopropanation. Both the inter- and intramolecular cyclopropanations were proposed to proceed via a reactive chiral ruthenium carbene intermediate. The enantioselectivities in these processes were rationalized on the basis of the X-ray crystal structures of closely related stable chiral carbene complexes [Ru(P*)(CPh2)] (2) and [Ru(P*)(C(Ph)CO2CH2CH=CH2)] (3) obtained from reactions of complex 1 with N2CPh2 and N2C(Ph)CO2CH2CH=CH2, respectively.

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Elderly individuals often fall because of poor muscle strength and reduced balancing ability related to muscle aging. However, it is unclear whether changes in muscle fiber types contribute to poor strength or imbalance. We studied age- associated changes in human skeletal muscle fibers using muscle biopsy specimens taken from 65 male and female Chinese patients aged 17-96 years. The muscle specimens were cryosectioned with alkaline triphosphatase staining at pH 4.4, followed by image analysis. We analyzed morphologic observations and performed quantitative analyses of the number, size, and area percentage of different types of skeletal muscle fibers and connective tissues. Types IIA and IIB muscle fibers decreased with age in the area percentage, fiber number percentage, and mean fiber area, whereas Type I fibers increased in area and number but not in size. Morphologically, Type II fibers appeared smaller and flatter. Our findings suggest deterioration in muscle quality and balancing coordination in elderly patients. We provide data to help determine treatments for reversing muscle fiber changes and reducing the number of falls and related fractures in patients.