(3 + 3) Cycloaddition of Oxyallyl Cations with Nitrones: Diastereoselective Access to 1,2-Oxazinanes
作者:Marie Cordier、Alexis Archambeau
DOI:10.1021/acs.orglett.8b00617
日期:2018.4.20
Oxyallyl cations are prepared in situ from readily available α-tosyloxy ketones and act as transient electrophilic partners in (3 + 3) cycloaddition with nitrones. Under mild conditions, this method provides a chemoselective and diastereoselective route to polysubstituted 1,2-oxazinanes. A stepwise process is proposed to rationalize the diastereoselectivity of this transformation.
由容易获得的α-甲苯磺酰氧基原位制备羟基烯丙基阳离子,并在与硝酮的(3 + 3)环加成中充当瞬态亲电子伙伴。在温和的条件下,该方法为多取代的1,2-恶嗪酮提供了化学选择性和非对映选择性的途径。提出了逐步处理以合理化此变换的非对映选择性。