The reactions of halocarbenes with pre-aromatic ketones 1, 2 resulted in cyclopropanation and deoxygenation products. The varying product ratio could be accounted for by a mechanism involving the carbonyl ylide interm...The reactions of halocarbenes with pre-aromatic ketones 1, 2 resulted in cyclopropanation and deoxygenation products. The varying product ratio could be accounted for by a mechanism involving the carbonyl ylide intermediate.展开更多
SUPER large gold deposits related to alkaline intrusions have been found in America,Canada,Australia,Papua New Guinea and elsewhere.Dongping gold deposit with superlarge potentialhas also been found in Shuiquangou alk...SUPER large gold deposits related to alkaline intrusions have been found in America,Canada,Australia,Papua New Guinea and elsewhere.Dongping gold deposit with superlarge potentialhas also been found in Shuiquangou alkaline complex intrusions,northwestern Hebei Province,China.One of the keys to resolving the possible genetic relationship between gold deposits andore-host alkaline intrusions is to determine their formation ages.This note dates the Shuiquan-gou intrusions with zircon U-Pb method.展开更多
DURING the past two decades Bordwell and co-workers have built up an extensive collection of the equilibrium acidity constants (pK_A) in DMSO solution which now includes over a thousand of organic compounds of a wide ...DURING the past two decades Bordwell and co-workers have built up an extensive collection of the equilibrium acidity constants (pK_A) in DMSO solution which now includes over a thousand of organic compounds of a wide range of structures. Later, Bordwell and Parker, as well as our group have developed the methods for estimating homolytic cleavage energies (BDE) of the acidic R-H bonds in DMSO, water, and in the gas phase, respectively, from properly designed thermodynamic cycles utilizing the pK_A and redox data which can展开更多
文摘The reactions of halocarbenes with pre-aromatic ketones 1, 2 resulted in cyclopropanation and deoxygenation products. The varying product ratio could be accounted for by a mechanism involving the carbonyl ylide intermediate.
文摘SUPER large gold deposits related to alkaline intrusions have been found in America,Canada,Australia,Papua New Guinea and elsewhere.Dongping gold deposit with superlarge potentialhas also been found in Shuiquangou alkaline complex intrusions,northwestern Hebei Province,China.One of the keys to resolving the possible genetic relationship between gold deposits andore-host alkaline intrusions is to determine their formation ages.This note dates the Shuiquan-gou intrusions with zircon U-Pb method.
文摘DURING the past two decades Bordwell and co-workers have built up an extensive collection of the equilibrium acidity constants (pK_A) in DMSO solution which now includes over a thousand of organic compounds of a wide range of structures. Later, Bordwell and Parker, as well as our group have developed the methods for estimating homolytic cleavage energies (BDE) of the acidic R-H bonds in DMSO, water, and in the gas phase, respectively, from properly designed thermodynamic cycles utilizing the pK_A and redox data which can
