Catalytic Allylation of Aldehydes Using Unactivated Alkenes
作者:Shun Tanabe、Harunobu Mitsunuma、Motomu Kanai
DOI:10.1021/jacs.0c04735
日期:2020.7.15
and a chromium complex catalyst, enabling catalytic allylation of aldehydes with simplealkenes, including feedstock lower alkenes. The reaction proceeded under visible-light irradiation at room temperature and with high functional group tolerance. The reaction was extended to an asymmetric variant by employing a chiral chromium complex catalyst.
Practical, highly stereoselective allyl- and crotylsilylation of aldehydes catalyzed by readily available Cinchona alkaloid amide
作者:Yuan Huang、Licheng Yang、Panlin Shao、Yu Zhao
DOI:10.1039/c3sc50973g
日期:——
constructed based on the Cinchonaalkaloid structure that promote highly stereoselectivereactions of allyl- and crotyltrichlorosilane with aromatic as well as aliphatic aldehydes (90–99% ee, >98% diastereoselectivity). The catalysts are available in a one-pot procedure in >70% yield from cheap starting materials and promote the allylation reactions at ambient temperature. Gram scale reactions with catalyst recovery
Stereoselective Total Synthesis of (−)-Spirofungin A by Utilising Hydrogen-Bond Controlled Spiroketalisation
作者:John E. Lynch、Shannon D. Zanatta、Jonathan M. White、Mark A. Rizzacasa
DOI:10.1002/chem.201002501
日期:2011.1.3
The stereoselective total synthesis of the spiroketal containing Streptomyces metabolite (−)‐spirofungin A (1) is described. A key step involved a spiroketalisation controlled by an intramolecular H‐bond which favoured the desired spiroketal 4 (13:1 ratio). The presence of the intramolecular H‐bond in 4 is possibly due to a 1,5‐alkyne–oxygen interaction. Other key steps include an efficient cross‐metathesis
Gold(I)‐Catalyzed Intramolecular Dehydrative Amination of Sulfamate Esters Tethered to Allylic Alcohols: A Strategy for the Synthesis of Cyclic Sulfamidates
作者:Yunjeong Park、Ji Sun Lee、Jae‐Sang Ryu
DOI:10.1002/adsc.202001330
日期:2021.4.13
An efficient synthesis protocol for cyclic sulfamidates has been developed via catalytic intramolecular cyclizations of sulfamate esters tethered to allylic alcohols. The reactions proceed smoothly at room temperature in the presence of (IPr)AuCl (5 mol%) and AgBF4 (5 mol%). This protocol features good to excellent yields, high selectivity, broad substrate scope, and mild reaction conditions. This
Efficient Synthesis of Dimeric Oxazoles, Piperidines and Tetrahydroisoquinolines from <i>N</i>
-Substituted 2-Oxazolones
作者:Yun He、Piyush K. Agarwal、I. N. Chaithanya Kiran、Ruocheng Yu、Bei Cao、Cheng Zou、Xinghua Zhou、Huacheng Xu、Biao Xu、Lei Zhu、Yu Lan、K. C. Nicolaou
DOI:10.1002/chem.201601471
日期:2016.6.1
practical method for the construction of heterocycles from N‐substituted 2‐oxazolonesthrough cascade, BF3⋅Et2O/H2O‐catalyzed reactions involving iminium ion generation and trapping by external or internal olefinic and aryl moieties is described. Mechanistic and computational studies revealed the strong protic acid HBF4 as the initiating catalyst for these cascade reactions. Providing access to novel molecular
为杂环的来自建筑的温和和实用的方法Ñ通过级联取代-2-恶唑酮,BF 3 ⋅Et 2 ø/ H 2涉及亚胺离子产生和由外部或内部烯属的和芳基部分捕获O形催化的反应进行说明。机理和计算研究表明,强质子酸HBF 4是这些级联反应的引发催化剂。这些过程提供了获得新颖分子多样性的途径,可以促进化学生物学研究,药物发现工作和天然产物合成。