Silver-Promoted Benzannulations of Siloxyalkynes with Pyridinium and Isoquinolinium Salts
作者:Jaime R. Cabrera-Pardo、David I. Chai、Sergey A. Kozmin
DOI:10.1002/adsc.201300443
日期:2013.9.16
efficient benzannulations of siloxyalkynes with pyridinium and isoquinolinium salts. Such reactions are successfully promoted by a stoichiometric amount of silver(I) benzolate under mild reaction conditions. This process proceeds via a formal inverse‐electron demand Diels–Alder reaction, followed by fragmentation of the initially produced bicyclic adducts to deliver a range of synthetically useful phenols
Non-Precious Metals Catalyze Formal [4 + 2] Cycloaddition Reactions of 1,2-Diazines and Siloxyalkynes under Ambient Conditions
作者:Chintan S. Sumaria、Yunus E. Türkmen、Viresh H. Rawal
DOI:10.1021/ol501254h
日期:2014.6.20
Copper(I) and nickel(0) complexes catalyze the formal [4 + 2] cycloaddition reactions of 1,2-diazines and siloxyalkynes, a reaction hitherto best catalyzed by silver salts. These catalysts based on earth abundant metals are not only competent, but the copper catalyst, in particular, promotes cycloadditions of pyrido[2,3-d]pyridazine and pyrido[3,4-d]pyridazine, enabling a new synthesis of quinoline
铜 (I) 和镍 (0) 配合物催化 1,2-二嗪和甲硅烷氧基炔烃的正式 [4 + 2] 环加成反应,该反应迄今为止最好由银盐催化。这些基于富含地球的金属的催化剂不仅有能力,而且铜催化剂,特别是促进吡啶并[2,3- d ]哒嗪和吡啶并[3,4- d ]哒嗪的环加成,使喹啉和异喹啉衍生物,以及环己烯酮与甲硅烷氧基炔烃的正式 [2 + 2] 环加成反应。
Synthesis of Eight-Membered Lactones: Intermolecular [6+2] Cyclization of Amphoteric Molecules with Siloxy Alkynes
作者:Wanxiang Zhao、Zhaobin Wang、Jianwei Sun
DOI:10.1002/anie.201200513
日期:2012.6.18
That's about the size of it: The title molecules react with siloxyalkynes in the presence of a Brønsted acid to deliver medium‐sized lactones through a [6+2] cyclization (see scheme; TIPS=triisopropylsilyl). This process is the first intermolecularsynthesis of such lactones and involves a sequence of several selective ring‐opening/ring‐closing events.
Palladium- and Nickel-Catalyzed Carbon−Carbon Bond Insertion Reactions with Alkylidenesilacyclopropanes
作者:Kay M. Buchner、K. A. Woerpel
DOI:10.1021/om901042j
日期:2010.4.12
promoted highly selective carbon−carbonbondinsertion reactions with di-tert-butyl-alkylidenesilacyclopropanes. Pd(PPh3)4 was demonstrated to be the optimal catalyst, allowing for a variety of carbon−carbon π-bond insertion reactions. Depending on the nature of the carbon−carbon π bond, the insertion reaction proceeded with either direct insertion into the carbon(sp2)−silicon bond or allylic transposition
Silver-Catalyzed [2 + 2] Cycloadditions of Siloxy Alkynes
作者:Randy F. Sweis、Michael P. Schramm、Sergey A. Kozmin
DOI:10.1021/ja048251l
日期:2004.6.23
We have described the first [2 + 2] cycloadditions of siloxyalkynes with a range of unsaturated carbonyl compounds. The reactions are efficiently promoted by substoichiometric amount of silver trifluoromethanesulfonimide and display excellent regio- and diastereoselectivity combined with a broad substrate scope. Our studies have established unambiguously the stepwise mechanism of this process and