Conjugate Addition Routes to 2‐Alkyl‐2,3‐dihydroquinolin‐4(1
<i>H</i>
)‐ones and 2‐Alkyl‐4‐hydroxy‐1,2‐dihydroquinoline‐3‐carboxylates
作者:Alex Kingsbury、Steve Brough、Antonio Pedrina McCarthy、William Lewis、Simon Woodward
DOI:10.1002/ejic.201901036
日期:2020.3.27
quinolin‐4(1H)‐ones to provide 2‐alkyl‐2,3‐dihydroquinolin‐4(1H)‐ones (14 examples, 54–99 % yield). Asymmetric versions require AlEt3 to Boc‐protected ethyl 6‐substituted 4(1H)‐quinolone‐3‐carboxylates (6‐R group = all halogens, n/i/t‐alkyls, CF3) and provide 61–91 % yield, 30–86 % ee; any halogen, Me, or CF3 provide the highest stereoselectivities (76–86 % ee). Additions of AlMe3 or Al(nC8H17)3 provide ≈ 45 and
在CuBr · SMe2 / PPh3催化下(5/10 mol%)RMgCl(R = Me,Et,n Pr,CH = CH 2,n Bu,i Bu,n C 5 H 11,c C 6 H 11,Bn ,CH 2 Bn,n C 11 H 23)容易地(–78°C)对Cbz或Boc保护的喹啉-4(1 H)-酮进行1,4加成,从而提供2-烷基-2-3,2-二氢喹啉- 4(1 H)-1 (14例,产率54–99%)。非对称版本需要AlEt 3到Boc保护的乙基6取代的4(1 H)-喹诺酮-3-羧酸盐(6-R基团=所有卤素,n / i / t-烷基,CF 3),收率61-91%,ee 30-86%; 任何卤素,Me或CF 3均可提供最高的立体选择性(76–86%ee)。AlMe 3或Al(n C 8 H 17)3的添加在母体中的添加提供≈45和≈75%ee(6-R = H)。配体(S)‐(BINOL)P–N(CHPh