Hydrazines and Azides via the Metal-Catalyzed Hydrohydrazination and Hydroazidation of Olefins
作者:Jérôme Waser、Boris Gaspar、Hisanori Nambu、Erick M. Carreira
DOI:10.1021/ja062355+
日期:2006.9.1
which the H and the N atoms come from two different reagents, a silane and an oxidizing nitrogen source (azodicarboxylate or sulfonyl azide). The hydrohydrazination reaction using di-tert-butyl azodicarboxylate is characterized by its ease of use, large functional group tolerance, and broad scope, including mono-, di-, tri-, and tetrasubstituted olefins. Key to the development of the hydroazidation
报道了 Co 和 Mn 催化的烯烃加氢肼和加氢叠氮化反应的发现、研究和实施。这些反应等效于 CC 双键与受保护的肼或偶氮酸的直接加氢胺化,但基于不同的概念,其中 H 和 N 原子来自两种不同的试剂,硅烷和氧化性氮源(偶氮二羧酸或磺酰叠氮化物) )。使用偶氮二羧酸二叔丁酯的加氢肼反应具有使用方便、官能团耐受性大、适用范围广的特点,包括单、二、三和四取代烯烃。氢叠氮化反应发展的关键是使用磺酰叠氮化物作为氮源和叔丁基过氧化氢的活化作用。发现该反应对于单、二和三取代烯烃的官能化是有效的,并且只有少数官能团是不能容忍的。获得的烷基叠氮化物是通用中间体,可以在不分离叠氮化物的情况下转化为游离胺或三唑。初步的机理研究表明,烯烃的氢化钴是限速的,然后是胺化反应。不能排除并可能涉及自由基中间体。然后进行胺化反应。不能排除并可能涉及自由基中间体。然后进行胺化反应。不能排除并可能涉及自由基中间体。
First Comprehensive Bakkane Approach: Stereoselective and Efficient Dichloroketene-Based Total Syntheses of (±)- and (−)-9-Acetoxyfukinanolide, (±)- and (+)-Bakkenolide A, (−)-Bakkenolides III, B, C, H, L, V, and X, (±)- and (−)-Homogynolide A, (±)-Homogynolide B, and (±)-Palmosalide C
作者:Timothy J. Brocksom、Fernando Coelho、Jean-Pierre Deprés、Andrew E. Greene、Marco E. Freire de Lima、Olivier Hamelin、Benoît Hartmann、Alice M. Kanazawa、Yanyun Wang
DOI:10.1021/ja0208456
日期:2002.12.1
dichloroketene with dimethylcyclohexenes has been used as the key reaction in an efficient, general approach to the bakkanes. New methods and methodologies that have been developed in this work include spiro beta-methylene-gamma-butyrolactonizations, a vicinal dicarboxylation, an angelic esterpreparation, a transesterification, an epoxy ketone double reduction, and a retro aldol-aldol approach to low-energy aldol
Syntheses with organoboranes. IX. Vinyl- and 1-alkenyldichloroboranes as ethylene and 1-alkene equivalents for the Diels–Alder reaction
作者:Marek Zaidlewicz、Jacek R Binkul、Wojciech Sokół
DOI:10.1016/s0022-328x(98)01175-9
日期:1999.5
Vinyl- and 1-alkenyldichloroboranes were used as dienophiles for the Diels–Alderreaction with representative aliphatic and cyclic 1,3-dienes. The organoborane adducts were transformed into the corresponding olefins either by protonolysis or by oxidation–mesylation–reduction. Direct protonolysis of the adducts gave in most cases mixtures of olefins whereas the reduction of mesylates with lithium triethylborohydride
Selective bond cleavage in the iron(III) chloride-catalysed photo-oxidation of olefins
作者:Tadashi Sato、Kazuo Maemoto、Akira Kohda
DOI:10.1039/c39810001116
日期:——
Iron(III) chloride-catalysedphoto-oxidation of substituted olefins gave either gem-dichloro-ketones or α,ω-dichloro-ketones selectively, depending upon the substitution pattern of the substrates.
Scope and limitations of the stereoselective homogeneous hydrogenation of methylenecyclohexanols by cationic rhodium complexes
作者:John M. Brown、Stephen A. Hall
DOI:10.1016/s0040-4039(01)80167-2
日期:1984.1
Homogeneous catalytic hydrogenation of 3-methylenecyclohexanol gives -3-methylcyclohexanol with 98% stereoselectivity. but low selectivity is observed for 2-methylenecyclohexanol and 2-methylenecyclohexanemethanol.